INTRODUCTION TO DIGITAL PHOTOGRAPHY:
Digital cameras have taken the photographic world by storm. They are smaller, lighter in weight, easier to use, and offer you more control over your images through the computer. Not to mention of course, there are no recurring film and processing costs associated with digital imaging. With an internet connection, it is very easy to share your photo memories with family and friends through e-mail, or even designing your own website or blog. As is the case with most advances in technology, there is a learning curve associated with the products that adds to the confusion in adapting to the new products. Instead of film, you need to be aware of MP (megapixels), MB (megabytes), storage media, downloading, and a host of other terms and practices. Fortunately, the essentials of taking pictures with a digital camera are the same as with a film camera. Whether using film or a digital sensor, you still have to select an ISO sensitivity, and then set the shutter speed and to ensure that the image properly imprinted. This introduction to digital photography workshop will help demystify some of the technology, terms, and techniques that are used in the new world of digital imaging.
1.01 How do digital cameras record an image? We are all aware of film, and we are very comfortable with the idea of placing a film cartridge in the camera, advancing the film, taking the pictures, removing the film from the camera and taking it to the drug store or photolab for processing. We may not understand the processes associated with turning negatives into pictures, but we accept the results, usually with great joy. In most ways, digital works the same way. Instead of film, we use a Flash Card or some other recording media in place of film. The taking of the pictures remains the same. Once you have recorded the pictures you want, you either transfer the images to your computer via a cable, or take the recording media out of the camera and put it into a reader or docking station connected to the computer. In place of film, a digital camera uses a light sensitive sensor to capture the image at the moment of exposure. Light hitting the sensor initiates an electrical charge that is then translated into digital data (bits and bytes). The image is then â€œwrittenâ€? to the recording media or flash card for storage. The sensor is comprised of photo detectors or pixels (picture elements). A 5 megapixel image is made up of 5 million pixel measurements imprinted upon the photo sensor chip in the camera. Generally, the more pixels there are, the clearer the image will be. However, it should be noted that it isnâ€™t simply a matter of the number of pixels but also the size and quality of the pixels that determines the overall sharpness, color fidelity and tonal range of the picture. Because digital SLR cameras generally utilize larger pixels that capture greater detail than those used in compact cameras, the SLR image will usually be sharper and overall better.
Pixels and Megapixels A digital image is made up of a matrix of picture dots each representing a specific color of the original scene. These dots are called “pixels” and refer to the number of “picture elements” contained on a camera sensor for recording an image. A 5MP image sensor is made up of 5,000,000 pixels. A 10MP is made up of 10,000,000 picture elements.
Compact cameras are designed specifically to be small in size to make them more portable. Sensors of digital compact cameras are substantially smaller than the sensors of a digital SLR. Consequentially, the pixel size in a compact camera is a lot smaller resulting in less image quality even though there may be the same number of pixels on the sensor. As a result, definition, tonal range, color saturation, may not be as good as an image from a SLR. Therefore, a 5MP or megapixel SLR is likely to produce a sharper, more detailed image than an 8 MP or 10MP compact camera. 1.03 Bits, Bytes, and Megabytes A “bit” is either a “1” or a “0”. It is either turned on, or turned off. A “byte” is made up of 8 Bits and there are 256 possible signal combinations in a single byte. Considering a photographic image is made up of millions of bytes, that is a lot of information! The term “bytes” is a computer term describing the amount of data that is stored within a file. A “megabyte” is 1,000,000 bytes. It is much easier to write or say 25.6 MB rather than twenty five million, six hundred thousand bytes. Letters, spreadsheets, and databases files are usually relatively small in size measuring up to several hundred kilobytes. Photographs and other graphic files are very
large by comparison as they are high resolution and in color which requires at least 3X more data – RGB (red, green, blue). It is not uncommon for a photograph to be upwards of 24 MB or megabytes in size. 1.04 File Compression For the best overall detail and color fidelity it is ideal to use camera original files. These very large files permit printing large prints for framing and display, but storing of the files takes up huge amounts of hard drive space. However, if all you really want to do is produce a few 4”x6” prints and or the occasional 8”x10”, it isn’t necessary to use large, original or “RAW” files. In order to conserve space on recording media in the camera, hard drives on computers, and storage media like CD’s and DVD’s, file compression software utilities are used to effectively reduce the overall size of the image file by up to as much as 80%. As we have already discussed, a digital image file is make up of millions of data points. File compression will discard 10%, 20% or more of the data in order to save space. When a compressed file is reopened, the computer software will replace the missing information by duplicating it to the pixels immediately surrounding the void area. Because there are relatively few pixels being interpolated, in most images the effect isn’t noticeable. The important thing to remember is that every time a compressed file is opened and then re-saved, there is additional compression. After several saves the amount of data that is lost will become apparent in any print. With this in mind, if you are going to work on a file repeatedly, then don’t use a compressed file until all of your work is complete and then only compress the file once. You may still open and close it all you want--just don’t save it again.
1.05 How does file compression work? As stated above, compression software discards a percentage of the image data every time the file is saved. So the first time you save a compressed file, 10% or 20% of the information is irretrievably lost. When you open that file and then close it again, you lose another 10% or 20%. It isn’t long before it becomes noticeable. The following exemplifies what different types of compression do. A – Original On Monday the weather was sunny. On Tuesday the weather was sunny. On Wednesday the weather was rainy. On Thursday the weather was sunny. On Friday the weather was sunny. On Saturday the weather was sunny. On Sunday the weather was sunny. B – Lossless compression (50% compression) 1 Mon2 3 4 1 Tues2 3 4 1 Wednes2 3 5 1 Thurs2 3 4 1 Fri2 3 4 1 Satur2 3 4 1 Sun2 3 4
C – Lossy (82% compression) Last week was mostly sunny.
Lookup Table 1 = On 2 = day 3 = the weather was 4 = sunny 5 = rainy
Types of File Compression
JPEG (Joint Photographic Experts Group) JPEG files can only record up to 8 bits per channel. Most digital SLRs record 12 bits per channel. Therefore, JPEG files lose 33% of information. JPEG is based upon â€œLOSSYâ€? compression JPEG rearranges image information into color and detail and then compresses color more than detail, as our eyes are more forgiving on missing color than missing detail. GIF (Graphics Interchange Format) ideal for web graphics o supports animation for web applications only supports 256 colors, therefore only good for small files. Not recommended for most general photographic applications
TIFF (Tagged Image File Format) Records in 8 bit (cameras) and 16 bit color (high end scanners) for greater color fidelity Compatible with most photo imaging and editing software Preferred format by most graphics and publishing houses TIFF uses lossless compression Superior to JPEG when printing larger than 8â€?x10â€? BMP (Windows Bitmap) Used by Windows operating system. Commonly used for Windows desktop wallpaper Not generally used for high quality photographic applications PSD (Adobe Photoshop) Ideal editing format as all your work is stored in layers for easier alterations Photoshop is the most widely accepted and used photo manipulation software in the world PDF (Portable Document Format) Universal file format that preserves all image, font, graphics, formatting of any source regardless of application or platform used to create it
Some digital compacts and all digital SLRs offer RAW Potential for 36 bit color in addition to 24 bit Smaller than TIFF files but holds far more detail than TIFF As the name implies, RAW format is the scene as initially recorded by the camera prior to any in-camera processing adjustments e.g. color temperature and white balance Considered by some to be the equivalent to a photographic negative as you can work extensively with the image to improve detail in shadows and highlights to achieve the most desired effects without any loss in overall quality You can reprocess RAW data over and over again without any loss in quality RAW formats vary from camera manufacturer to manufacturer so not all third party photo editing software Third party applications will not necessarily open and work with all RAW files
2.01 Compact Advances in digital technology have permitted camera manufacturers to significantly reduce the overall size of cameras. Traditionally, one of the greatest drawbacks to people taking more pictures was the inconvenience of lugging around a bulky camera and camera case. It was just easier to leave the camera at home. Small, flat chips and circuit boards have replaced the traditional film canister or cartridge allowing cameras to be built to fit in the palm of your hand and even into a cell phone. Many of today's compact, auto focus cameras are of a rangefinder type design. They use a viewfinder for the operator to look through for framing the picture. There are two "bug eyes" which control the focusing of the camera. One "eye" emits an infrared beam that reflects off the subject and is received by the other "eye". In this manner, the camera "measures" the distance and sets the lens. With a compact camera, the photographer is viewing the subject through a window above and/or off to the side of the taking lens. The offset view makes it difficult to properly centre the subject. Consequently, compact type cameras are limited in their use for close-up pictures. This effect is called parallax. Most compact cameras have a secondary line or centre spot in the viewfinder to be used as a guideline for framing close-up subjects to correct for the parallax.
SLR (Single Lens Reflex)
The Asahi Pentax company in the late 50â€™s introduced the single lens reflex camera (SLR). The SLR allows the user to see through the taking lens of the camera for setting distance and framing the image exactly as it will be recorded on the film. The camera uses a system of mirrors situated in the top of the camera body to reflect the image from the film plane, through the penta-prism system, and out to the user's eye. The main mirror flips out of the way at the instant of exposure permitting the light to be recorded on the film. The development of the SLR (through the lens viewing) greatly expanded the flexibility of the camera. Because you are seeing exactly what will be recorded on film, you have the choice of using a very wide range of lenses and accessories. Lenses can be as wide as a fish-eye (210 degrees) and as powerful as 2,000 mm. In addition, it permitted the adapting of the cameras to microscopes and telescopes, as well as numerous other filters and accessories. Throughout the past 50 years, significant advances have been made in developing improved and reliable auto exposure systems and more recently, automatic-focusing systems. Today's cameras, both viewfinder type and SLR, provide the user with the easiest to use, most repeatable consistency in results ever.
2.03 Pro-sumer Recognizing the desire of many photo-enthusiasts to have the functionality of a SLR camera in a smaller size package, the manufacturers developed a category of digital cameras called Prosumer cameras. These cameras incorporate many “professional” features of an SLR like longer optical zoom lenses than the compact with the convenience, smaller size, and lighter weight of a “consumer” compact. Most Prosumer models have a larger sensor chip allowing them to capture more detail than their compact counterparts. So an 5 MP prosumer camera will usually outperform and 8MP compact in sharpness and available degree of magnification.
3.00 AUTO EVERYTHING What do all the buttons do?
Red Eye Flash Reduction "Red-Eye" is one of the most annoying photographic artifacts that can ruin an otherwise great picture. It causes favoured children and grandchildren to appear demonic. Because the flash is located on a parallel axis, and in very close proximity to the lens of the camera, the light emitted by the flash reflects directly back from the retina of the subject's eyes recording them as glowing red orbs.
In an effort to minimize this effect, the camera manufacturers incorporate specialized Red-Eye Reduction circuitry that causes a "pre-flash" or "strobing" of light to contract the pupil of the eye. "Reduction" is the operative when speaking of Red Eye Reduction flash circuitryâ€”it reduces red eye, not eliminate it.
Because the pupil is contracted, there is less red light reflected from the retina. In other words, "red-eye" can still occur, the effect is merely minimized. In order for the camera to emit sufficient to light to cause the subject's eyes to react, there is a notable delay between you initially depress the shutter release and when the camera will actually take the picture. This delay can cause some frustration and an occasionally missed picture. 3.02
Flash On/Fill Flash Anytime the camera perceives an acceptable amount of light to take a picture without flash, it will default to a no flash exposure. Although this is acceptable for most outdoor pictures, activating the FLASH FILL, or FLASH ON, override when taking a portrait in bright sun can help lighten the shadows thereby reducing contrast and improving the picture.
Another instance where using FLASH ON occurs indoors. During the day, if you are taking a picture towards a window, the light of the window will likely cause the camera to default to no flash. This will result in your subject being underexposed. In such circumstances, activating the "Flash On" will ensure proper illumination of your principle subject.
Flash Off In addition to Flash On, some cameras also incorporate FLASH OFF circuitry. This is most commonly used when attempting to take a time exposure or attempting to take a natural light exposure such as the family around a campfire. Because these are low light picture situations, the camera will use a slow shutter speed. In order to reduce the risk of camera movement, brace the camera in the best possible manner.
Infinity lock Like automatic exposure, auto focus systems are almost infallible. However, there are some circumstances where the camera may fool you. By example, taking scenic pictures through a window of a car or bus may cause the camera to focus on the glass. Instead of getting a nice, sharp picture of the landscape, you end up with a picture of an insect splattered on the windshield.
Likewise, when taking pictures at a zoo, it can happen that the camera may focus on the fence rather than the animals in the enclosure. In such circumstances, it is advisable to activate the INFINITY LOCK in order to ensure that the camera will focus on its' furthest distance setting.
Most cameras are designed to focus from 4' to infinity. There are occasions when it is desirable to take pictures of small objects or photograph another picture. With most cameras, this necessitates being able to focus the lens down to less than 4 feet. Cameras equipped with MACRO have the ability to do just that. This will permit you to take a picture area roughly equivalent to 8"x10" within the full frame. 3.06
Self-Timer All too often, there is one person left out of the annual family photograph--the photographer him/herself. The SELF TIMER option on many cameras will delay the actual activation of the shutter by about 10 seconds. By utilizing the SELF TIMER function of the camera, one can set the camera up on a tripod, shelf or table top, depress the shutter release and have sufficient time to move into the picture.
In this self-portrait, the camera was secured on a tripod and the self-timer was set to 10 sec. This gave me plenty of time to get from the camera to my preselected position. The camera lens had already been focused to that distance, and the auto-focus turned off. The self-timer can also be used when taking time exposure photos. During long exposures, having your hand on the camera may be enough to cause some motion and blurring of the image. With most digital cameras, you are able to programme the length of exposure you want and then activate the self-timer and step away from the camera. Presto! No more camera shake. By example in this waterfall shot, the shutter speed was set for a Â˝ sec. exposure in order to have the water blur into a milky white stream. With the camera mounted on a tripod, the self-timer was used to release the shutter without risking the pressure of my finger shaking the camera during exposure.
PARTS OF THE CAMERA
A camera does not need to be sophisticated in order to take great pictures. In fact, a simple shoebox with a pinhole at one end and a film holder at the other end can take exceptional images. However, today's camera consists of many parts some of which may need to be adjusted, calibrated or activated by the user. In becoming familiar with the basic operating parts of the camera, we can clear away some of the jargon one hears and uses in photography and also learn what can be changed to improve your pictures. 4.01 Shutter The shutter controls the amount of time light hits the film. In rangefinder type cameras, the shutter is normally found within the lens itself or immediately behind the lens. As a rule, these are multiple bladed "leaf" shutters. Leaf shutter cameras can synchronize with electronic flash at any shutter speed. In a SLR camera, the shutter is found immediately in front of the film at the focal plane of the camera. Hence the name "focal plane" shutter. This type of shutter often consists of two or more curtains that move across the film plane to expose the film to light. The distance, i.e. duration in time between the two curtains, determines the shutter speed. Generally, most pictures are taken at or about 1/125 sec. This speed is usually fast enough to prevent camera shake from blurring the image when using a normal lens. For action photography and/or use of stronger (telephoto) lenses, a higher shutter speed is required.
4.02 Shutter Speed Control On a manual camera, the shutter speed is selected with the shutter speed dial. The usual range of speeds available are 1", 2", 1/4", 1/8", 1/15", 1/30", 1/60", 1/125", 1/250", 1/500", 1/1,000", 1/2,000"...etc. It is important to note that the transition between each pair of speeds is nominally a factor of 2 i.e. 1/60" is 2 the time of 1/30". 4.03 Shutter Release The shutter is triggered by the shutter release. Normally located on the top right deck of the camera, the shutter release should normally be easy to depress and smooth in action. In taking the picture, it is important to "SQUEEZE" the shutter release to reduce the potential for camera shake.
5.01 Eliminate Camera Shake In order to obtain good, clear, sharp results, it is essential to keep the camera as steady a possible. Ideally, a tripod should be used at all times, however this is impractical in many instances, not to mention, very inconvenient. A monopod is very lightweight alternative, but it is still somewhat cumbersome. Hand holding a camera when using wide angle, normal or short range zoom lenses, it is advisable to select a shutter speed of 1/60 sec. or shorter duration. When using longer telephoto lenses, the concern is greater because the degree of shake or movement is compounded by the telescopic effect of the lens. A rule of thumb is to use a shutter speed equal to, or greater than, the focal length of the lens. By example, for using a 200mm. lens, you would use 1/250 sec. shutter speed or faster. 5.02 The Human Tripod Although it may feel somewhat uncomfortable at first, one of the easiest ways to improve your pictures is to learn to hold the base of the camera and lens in the palm of your left hand. Place the camera in the palm of your hand. Your fingers should comfortably grasp the focus barrel, aperture, and/or zoom ring of the lens. This allows you to manipulate the lens fully by your left hand leaving your right hand free for the shutter release and adjusting the camera controls. It also forces your arms in close to your body. Standing with your feet slightly apart, you will give the camera the greatest support, almost like forming a tripod with your body. If possible, lean against a tree, a car, or a fence, to gain greater stability.
5.03 Beans to Supports As much as possible, it is advisable to use something stationary to lean against or set the camera on as a support. Fence posts, rocks and tree branches all make good supports. Your camera strap can also be used as a support tool when wrapped around your wrist or used to pull the camera into your shoulder for increased bracing. Some photographers like to carry a few beanbags in their car when going out to do roadside photography. They are handy to have to set down on the roof, hood, or trunk of the car to place your camera on to help you keep the camera stable. Personally, I have a sleeping bag that rolls up into a very small package that I will sometimes use as a support when using a long telephoto lens. In all instances when you are taking handheld pictures, it is a good idea to be conscious of your breathing and try to time the pressing of the shutter release near the end of exhaling. At this time, your entire body is more relaxed. This coupled with a pressing or squeezing action to activate the shutter will help beat the "fuzzies" in your pictures. 5.04 Panning Your Pictures Sometimes, a degree of blur can help convey an impression of motion or speed. An effective way to create this impression is called "panning". Panning is moving the camera in synchronization with the subject while using a relatively slow shutter speed (usually around 1/15 sec.) to expose the picture. By keeping the camera centered on the subject throughout the exposure, the subject will remain relatively sharp while all other elements of the photograph will become blurred. The secret to creating a successful "pan" shot is to follow the action ALL the way through the exposure and beyond. Don't simply stop at the instant of exposure, your subject is still in motion. Keeping the movement smooth and constant will greatly enhance your chances for a successful picture.
A camera is a precision instrument. As such, it needs to be maintained properly and carefully cleaned. Understandably, the lens must be kept clean of fingerprints, dust and smears. Most of the time dust particles can be brushed and blown off the lens with a blower brush. 6.01 Cleaning Lenses For fingerprints and smears, it may be necessary to use a cleaning cloth and/or a liquid lens cleaner. Before using a cloth, make certain to remove all loose dust particles first. Any grit could scratch the surface of the lens causing irreversible damage to the coatings. The coatings on the lenses are quite durable however when using liquid lens cleaners you should NEVER apply the fluid directly to the lens. It can become trapped at the edges of the mount that secures the lens element and over time may destroy the coatings. Instead, apply a few drops of fluid to a cleaning cloth and then gently swipe the cloth on the lens. Then buff the lens applying only as much pressure as necessary to remove the print or smear. Once cleaned, it is advisable to put a UV filter on your lens. It will help reduce haze in your photographs, but more importantly, it protects your lens from potentially damaging scratches or fingerprints. It also offers some protection For the front lens element in the event the lens gets bumped or dropped. It's a lot cheaper to replace a filter than it is to rebuild a lens. 6.02 Blow--Don't Go If you are using an interchangeable lens camera, you may find some dust or a hair that has fallen on the mirror behind the lens. Internally, you should only use a blower brush to blow any dirt or grit out of the film chamber, around the shutter
areas. NEVER TOUCH THE SHUTTER BLADES OR SENSORS! In many cameras, the blades are made of very thin metal alloys and extremely sensitive to touch. This is by far the most common cause of shutter failure and is very expensive to repair. SLR cameras use front surface mirrors. These mirrors are also very sensitive and can very easily be scratched. Therefore, it is imperative that under no circumstances should you use any potentially abrasive method to clean the mirror. It is best to only use air to blow dust and dirt from the mirror chamber area. It should also be noted that the propellant used in cans of compressed air may react with the mirror permanently damaging the surface. Great care should be exercised at all times when the lens is off the camera and the mirror chamber is exposed.
Film sensitivity (speed)
Depending upon the ISO setting you select, the sensor chip will react faster or slower to light. This rate of change is measurable under laboratory conditions and is assigned an exposure index or “film” speed. Up until about the seventies, this number was referred to in North America as ASA(American Standards Association) and in Europe as DIN (Duetches Industrie Norme). The photographic industry then adapted a universal measurement system and corresponding nomenclature for film speed that today is known as ISO (International Standards Organization). The higher the number, the more sensitive the film is to light. Therefore, a 400 ISO is twice as sensitive to light than a 200 ISO . Conversely, a 100 ISO is half as sensitive as the 200 ISO. Why are there so many ISO speeds to choose from? There is a trade off in choosing to use a higher sensitivity rating. The higher the ISO setting, the less detailed the image will become. This frequently results in the image having a very speckled or “grainy” appearance. There will be less color saturation and lower contrast to the image leading to further visual degradation. The higher the ISO, the "grainier" your pictures will be. The slower speeds, when properly exposed, give sharper, clearer, more detailed pictures. In general, most people have standardized on using ISO setting of 200. This offers the sharpness and clarity of being a moderate speed film combined with extended sensitivity for action and/or flash picture range.
The higher speeds are ideal for use under marginal lighting conditions, for stopping action in sports photography, and where extended flash range is required. Your choice is predicated by the circumstances you are going to be shooting under and the degree of sharpness and clarity you require as an end result. 7.02
Cameras are colorblind
The camera “saw” grey making this a daylight scene.
As we all know, the volume of light varies constantly throughout the day from dawn to dusk to night. Since the sensitivity or “film” speed is fixed, then it follows that there is a need to be able to evaluate the volume of light so that it can be balanced to that degree of sensitivity. In most of today's cameras, this is done by a built-in light meter.
The picture was taken at twilight.
Most meters are built with the assumption that majority of photographs will be taken of an average scene. In other words, there will be a natural balance of both light and dark tones. If it were possible to stir all the tones, hues and range of brightness values together, the resultant color would be a moderate dark gray. Light meters are designed with the assumption that this "gray" will represent the average scene, and because most pictures are taken in such environments, they work quite well--most of the time. However, upon occasion, you will want to take a picture that is out of balance in color composition. By example, an aircraft flying overhead at and air show, or an ice skater performing on white ice, or a water skier slicing across dark blue water. In each of these scenes the "balance" is altered either darker or lighter than gray. In such circumstances, you will have to interpret the scene for yourself and
override the meter to allow for the imbalance. If the scene is dominated by light tones, the meter will attempt to darken down the exposure to achieve gray causing underexposure. To compensate, you would have to change the exposure towards over exposure. Conversely, if the scene is dominated by dark colors, the camera meter will attempt to over expose the scene. The required compensation will be to reduce the exposure. In other words, light meters are reliable the majority of the time, however, they are color blind and as such, under some circumstances adjustments to the meter reading may have to be made. 7.03 The Balancing Act To achieve the best picture possible, you need to balance the variables that you can control i.e. aperture setting and shutter speed. The aperture controls the volume of light getting through the lens and onto the film. The shutter speed determines the length of time the light will strike the film or sensor. Volume + Time = Exposure (ISO). The key to good exposure is to balance your choice of lens f-stop with the proper shutter speed in relationship to the sensitivity or ISO you have chosen to use. If you envision a teeter-totter with the ISO speed as the fulcrum, the lens aperture (volume) is on one side, and the shutter speed (time) is on the other. This gives you a good mental picture of how exposure works. Given the teeter-totter image, if you chose to decrease (shorten) the shutter speed to stop action, the volume of light will have to be increased to compensate. Conversely, if you chose to increase the exposure time, the volume of light (aperture setting) will have to be reduced (smaller lens opening).
ISO Setting: Meter Reading: Aperture 1.4 2.0 2.8 4.0 5.6 8.0 11.0 16.0 22.0 32.0 45.0 64.0
200 ISO f8.0 @ 1/60 sec. Shutter Speed 1/2000 1/1000 1/500 1/250 1/125 1/60 1/30 1/15 1/8 1/4 2 1
7.05 Rule of Thumb for Exposure What if you donâ€™t have a hand held meter and you need to take a picture? Is there another way to calculate your exposure? The answer is yes. Although it will only give you an approximate exposure, using the following rule of thumb can make the difference between getting a picture or no image at all. The rule of thumb for exposure is to select 1/(film speed) as your shutter speed and then choose a lens aperture that most closely represents your type of daylight condition listed below. Shutter Speed 1/ISO
Lighting conditions Bright sun on white sand or snow Bright sun, average scene Cloudy bright Overcast Open shade Dawn or dusk
Lens Aperture f22 f16 f11 - f 8.0 f5.6 f4.0 f2.8 - f 2.0
Exposure Modes Todayâ€™s cameras have very sophisticated exposure systems built into them to set both the shutter speed and lens aperture. With the aid of advanced algorithms, the camera will compute a combination that will adjust the lens opening allowing the use of a sufficiently high enough shutter speed to permit hand holding the camera. This is
commonly referred to as the “Program” mode designated by the letter “P” on your camera control dial. 7.07 Aperture Priority Although “Program” mode will work in most instances, there are many circumstances when you will wish to influence the exposure settings but still have the exposure value computed automatically. By example, you may want to be able to stop action or intentionally increase (or decrease) the depth of field. This is referred to as “Aperture Priority” and is generally designated by the letter “A” (or “Av”) on the control dial. To stop action in sports, select the largest lens opening possible. To do this, you chose a large shooting aperture of f4.0, f2.8, or f2.0.This will result in the camera using the highest shutter speed the lighting conditions and “ISO” setting will permit. Two techniques where you need to control the aperture are; i) sports and ii) increasing depth of field. For sports, using the maximum aperture ensures the camera will choose the highest shutter speed the scene will allow. To increase depth of field, you need to choose the smallest aperture setting the scene will allow such as f8.0, f11, or f16.
Shutter Priority Conversely, there will be times when you want, or need, to have a pre-selected shutter speed. One prime example is when using electronic flash outdoors—see “Synchro-Sun flash”. Your camera may necessitate using a specific shutter speed when using flash. Failing to select the correct shutter speed may result in over or under exposure, or even possibly no picture at all.
Another instance choosing a predetermined shutter speed is beneficial is when you intentionally want to use a slow shutter speed to generate some blur to the image to illustrate motion. The most classic example of this technique is in taking pictures of a waterfall where the slow shutter speed (generally around ½ sec.0 will create a milky white “flow” to the water. 7.09 Manual For the photo enthusiast, or control freak, many of the high end “Prosumer” and Professional cameras offer you the opportunity to manually set both the aperture and the shutter speed so you can still make all the mistakes by yourself. There are some circumstances when any and all the automatic settings computer technology offers simply doesn’t deliver the desired effect. One example of this is when trying to take a “moonscape” photograph. The night sky is almost black, but the camera’s automatic systems will insist upon turning it a light grey. To fully override the automatic settings, select “M” and then dial in the shutter speed and aperture setting you wish to use.
As critical as the technical aspects of exposing an image are, nothing has greater impact on making or breaking a photograph as composition. You can have a perfectly exposed picture, but if your subject's head is cut off or there's a telephone pole growing out of it, the impact of the image is lost. For this reason, it is essential to be mindful of EVERYTHING that is in the viewfinder and that you position the camera to compose the elements in such a way as to tell the whole story. 8.01
Horizontal vs. Vertical
Our perspective of the world around us is horizontal. Buildings and landscape follow the horizon line causing us to see breadth more than height even though our peripheral vision is almost 180 degrees both vertically as well as horizontally. Because it is our natural format of viewing, cameras are built specifically to give a horizontal image. Psychologically, we generally find this format of framing to be natural and therefore calming and peaceful to look at.
A very effective and easy way to make a picture more dynamic is to simply use the camera vertically. Because it turns our normal perspective on end, the vertical format catches our attention. As a result, it suggests not only height but also strength or power. This type of framing is particularly useful when shooting individual portraits as it enables the photographer to isolate a subject eliminating potentially distracting background material that may be off to the sides. Turning a camera on its' side can make handling awkward. It is therefore very important to make certain that you do not have a part of your hand blocking the flash or a finger or the camera strap in the path of the taking lens of the camera when using a compact rangefinder type camera. 8.02
Alter the Horizon Line Once you have chosen either a horizontal or vertical format, the next element to look at is the where you would like to position the horizon line.
In school, we learn to read from top to bottom and from left to right. As a result, our "normal" method of viewing follows the same pattern. Providing there are no distractions, our eyes will quickly scan an image and then pass on to something else. However, if there is a break in the balance from side to side or top to bottom, the eye will be drawn to it the point of imbalance. One key to grabbing a viewerâ€™s attention is to position your principle subject off centre and on a plane that breaks the "norm".
8.03 Rule of Thirds An easy way to apply this principle is to visualize splitting your scene in the viewfinder into thirds from the top to the bottom and from left to right. This gives you a choice of two potential horizon lines either horizontally or vertically. By emphasizing either the sky (by using the lower horizon) or the foreground (the upper horizon), you have broken the normal symmetry and therefore have created attention. In addition, applying the "Rule of Thirds" creates four intersecting points that are often referred to as "dynamic points of interest". Placing your principle subject on one of these four points again breaks the norm and causes the eye to stop. 8.04 Filling the Viewfinder One of the seemingly most difficult aspects of composition for many people to learn is the skill of learning to see in the viewfinder what the camera sees. It is our nature to concentrate on things that are important to us and completely disregard everything else. Unfortunately, in photography, this practice can result in your subject being very small and, in extreme cases, indistinguishable from the surrounding area in the photograph. Today, cameras work very much on the WYSIWYG principle--What You See Is What You Get. So if your subject only occupies the centre 10% of the
viewfinder, you can count on the remaining 90% of the dead space dominating the photograph. It is simply a matter of adopting the discipline of being very aware of EVERYTHING that is (and that which is not) in the viewfinder. After all, you are taking everything in that scene no matter how big or how small and you are reducing it to an area of 24mm X 36mm (1" x 1.5"). Talk about "Honey, I shrunk the kids!", in photography it's not just the kids, it's the house in the background, the tree on the left and the entire backyard to the right. Coupled with this element of balance is the preoccupation of many to leave the face of a subject right dead centre in the viewfinder. This has resulted in the unnecessary amputation of more feet, legs, hands and arms then all the wars of all history combined. With most cameras, once you have set the distance you are free to position your subject anywhere within the frame-lines as you like. Therefore make use of the ENTIRE viewfinder to include all ten fingers to complete your image. 8.05 Balance Leave sufficient room around your subject to complete the action. Although at first reading this may seem to contradict what is stated above, it is actually an expansion of the same principle. You are going to utilize the composition of your photograph to allow completion of the story. By example, in an action shot, leave slightly more room in front of where the action or movement is occurring. Psychologically, this provides
some area for the movement to continue on to. It allows the viewers imagination to complete the action. When taking a portrait, leave room for your subject to look into--it will look more natural in addition to giving the eyes a reason to be set in that direction. Better yet, have your subject look at something specific and include it in your photograph. It tells a more complete and compelling story. 8.06 Natural Framing There is nothing more depressing than a bland, shapeless, gray, overcast sky. Unfortunately, this is generally an unavoidable part of a misty type scene. Using a high horizon line simply means that the top of your picture disappears into nowhere. However, by repositioning the camera in such a way as to include a part of the trunk of a tree with its' lowest limb cutting across the top of the image provides for a natural framing which contains the viewers attention within the scene and reduces the amount of sky in the final picture. You can even go so far as to have someone hold a small branch close enough to the lens to keep it out of focus but still discernible and natural in appearance. The point to remember is to incorporate elements of the scene to keep the attention directed towards your subject. If you are shooting out of a window in the house, include the window frame as a part of the photograph. Trees, bushes
and shrubs all make tremendous natural framing elements to enhance a view and/or disguise extraneous matter and empty space. Most importantly, make use of the entire viewfinder. 8.07
Another means to utilize the natural environment of the scene to attract and hold attention is to make use of leading lines. A roadway cutting diagonally through photograph can make a natural "path" for the observerâ€™s eye to follow towards your subject or main point of interest. Just as is the case with balance, a photographer will look for patterns in the scene that help enhance the photograph. A row of trees, incorporating a line of buildings along a street, the guard rails of a bridge, railroad tracks, hydro poles and wires, there is virtually no end to elements that can be utilized as leading lines to create greater attention in your images. Using a 35mm or even wider angled lens will make the effect even more dramatic.
S-Curve It is a cold, brilliant winter's day. There, through the ice and snow sits a red aluminum boat, partially sunk in the stream—an element of a forgotten summer. Closer in, shadows cast by snowdrifts and trees on the shore dance upon the fresh snow.
In this scene, there are innumerable photographs that could be taken. However, to take a general scenic shot with all the various elements portrayed, there should be a common element that "ties" the various components together. In this instance, selecting a camera view point which allows the eye to enter the scene from the lower left and then wind its’ way up past the boat and on through the scene in an “S” path draws the viewer up and eventually out of the gap at the top. The entire photograph gives relatively equal and balanced attention to each area of interest. 8.09 In the beginning… One of the difficulties in bringing an image to life in photography is that it is a two dimensional representation of a three dimensional scene. With only height and width making up the final product, how can you create the illusion of depth? Just as we were told in elementary school, every story has a beginning, middle, and an end. The beginning introduces the reader to the story. The middle tells the story. And, the end completes the story.
As every picture tells a story, it only makes sense to include these elements into your photographic composition. The foreground is the beginning. mid-range elements represent the middle of the story. And, of course, off in the distance is the “end”. By giving the eye a path to follow (either leading lines or “S” curve), you can help lead the viewer through the “depth” of the photograph. 8.10 Changing Perspectives By far the majority of pictures are taken from eye level. I guess that makes sense since we use our eyes to frame the picture. However, there exist unlimited opportunities to be found in raising or lowering your perspective. Yes, this does mean squatting down, or even laying down to take the picture from a very low camera angle, or finding an elevated position by standing on the hood of a car, or climbing a tree. If you want to add a new and far more exciting dimension to your kids’ photos, try taking the pictures from their level. Go ahead, squat down and look them right in the eye. It's good for your circulation. Furthermore, you will reopen a vantage point to the world which too many of us have long ago forgotten.
8.11 Panning Your Pictures Sometimes, a degree of blur can help convey an impression of motion or speed. An effective way to create this impression is called "panning". Panning is moving the camera in synchronization with the subject while using a relatively slow shutter speed (usually around 1/15 sec.) to expose the picture. By keeping the camera centered on the subject throughout the exposure, the subject will remain relatively sharp while all other elements of the photograph will become blurred. The secret to creating a successful "pan" shot is to follow the action ALL the way through the exposure and beyond. Don't simply stop at the instant of exposure, your subject is still in motion. Keeping the movement smooth and constant will greatly enhance your chances for a successful picture.
The greatest advantage to using an SLR type camera is that you are viewing the picture through the actual lens on the camera. Consequently, you can put any number of lenses on your camera to take in a wider panoramic view of your subject or zero right in on a very specific point of interest. Today, both the original camera manufactures and the "off brand" manufacturers make a wide array of lenses to fit your SLR camera. There is everything from 210 degree Fisheye lenses to 2000mm telephoto lenses. You can even get adapters to allow using your camera mounted to a telescope for astral photography or a microscope for photomicrography. 9.01 Normal, Wide & Tele Technically, lenses fall within one of three general categories--normal, wide angle and telephoto. A "normal" lens renders the elements of the photo generally as they are seen without a camera. In order to do this without noticeable distorting the image, the focal length of the lens is calculated to be approximately the same size as the diagonal of the image area of the film. A 35mm image measures 24mm x 36mm, the length of the diagonal to that area is 43.26mm. Therefore, a "normal" lens for a 35mm camera is approximately 45mm in focal length. A wide-angle lens is optically designed to expand the area of view within the same format. In order to achieve this, the lens causes everything to look smaller. A focal length of 35mm or less is considered to be a wide-angle lens. Most 28mm and 35mm lenses generally retain a normal perspective whereas lenses of 24mm or less may show distortion unless the lens is held perfectly level. Lower quality, ultra-wide angle lenses (20mm or less) frequently exhibit barrel distortion that is curving of the vertical and horizontal lines. It is most noticeable the closer the lines are located to the outer edges of the picture frame.
Telephoto lenses have a focal length greater than 55mm. The optical design of these lenses magnifies the image. As the image is still recorded within the 24mm x 36mm format of the camera, less area of the scene makes up the final picture. Lenses up to about 105mm generally render a normal perspective and for this reason, are very popular as portrait lenses. Beyond the 105mm length, compression becomes more notable. This compression in longer lenses is often used to make the background appear to be closer to the subject. 9.02 There's never enough zoom! In the sixties and seventies, zoom lenses came into vogue to get around the monster camera bag problem. At the time, the designs would only permit straight telephoto zoom lenses or straight wide angle to wide-angle lenses. These lenses were quite large, heavy and more often than not, produced comparatively poor images. With the advent of computers, miniaturization quickly became the norm. A 70-210mm zoom lens of the sixties would weigh a couple of pounds and measure 12" to 14" in length. With computer design, these lenses now weigh a few ounces and are less than 4" in length. In addition, computers have made it possible to refine the optical purity of the lenses to a point where there is virtually no image quality loss from a zoom lens when compared to a fixed focal length lens.
Another benefit is that computer designing permitted the invention of wide angle to telephoto zoom lenses. So that now, one lens can easily replace up to five or six fixed focal length lenses of the past. Several manufacturers offer 28-300mm zoom lenses. This one lens will be able to cover everything from home interiors to hummingbirds in flight in one smooth action.
9.03 Perspective controllers In discussing lenses and their focal lengths, it is noted that a normal lens shows very little distortion because the lens matches the diagonal of the recorded film image. A telephoto lens magnifies the scene, zeroing in on the primary subject. In so doing, there is a degree of compression when using a telephoto lens. Visually, this is a closing of distances and loss of depth. The greater the focal length of the lens, the more apparent the compression becomes. A wide-angle lens reduces the size of the subjects in the scene and expands distances. The wider the angle of the lens, the greater the distortion becomes. In particular, ultra wide-angle lenses will show significant barrel distortion, which is most notable to the outside of the frame and/or the horizon line if the lens is not held level. Although these characteristics are often considered to be limitations of the lenses, more often than not, they can be utilized as composition tools to enhance a photograph. The compression of the telephoto lens helps to close the distance between the nose and ear in portraiture. By using a 105-135mm lens, you can subtlety alter a persons appearance to flatten their nose slightly. It's cheaper than plastic surgery, and you'll be considered as a photographic genius. Another benefit to using a telephoto lens is that the area of sharpness from front to back (depth of field) is reduced. This attribute of telephoto lenses helps isolate your subject by making it very sharp against a blurred background and/or foreground. With extreme telephoto lenses, 300mm or longer, compression is quite pronounced. This effect is often utilized to give emphasis to atmospheric conditions. Most notably are shots of heat vapor rising from a steaming highway at sunset on a hot day or to compacted smog vapor to illustrate pollution. The
vapor will be compressed to the point of appearing like waves of transparent bands in the photograph. The expansive characteristic of wide-angle lenses can be used to emphasize size and depth. By example, wide-angle lenses are frequently used in real estate photography to make rooms look larger and more inviting. A little three-room bungalow can take on the appearance of a mansion with the right combination of lenses and lighting. The other advantage of a wide-angle lens is its ability to extend the range of sharpness (depth of field) in a photograph. At minimum aperture (high f-stop number), everything from the nearest foreground to the most distant background will appear to be in sharp focus. This is frequently ideal in environments where you want to show a lot of detail throughout the entire image such as a furnished room. It is also advantageous in close-up and small product photography where optimum sharpness is required over the length and breadth of an object.
10.0 DEPTH OF FIELD You are on the beach. It is a brilliantly sunny day. The sand is gleaming white. Off in the distance, you see someone walking towards you. In an attempt to see them more clearly, you shade your eyes. They are still not quite distinguishable, so you squint. By reducing the glare and restricting the light getting through to your retina, you are able to make out who is approaching.... Itâ€™s night. You hear a strange noise. Startled, you are instantly awake! Your eyes haven't adjusted to the absence of light yet. Slowly, almost imperceptibly, as the pupils of your eyes expand, you become visually aware of your surroundings one item at a timeâ€Ś I apologize for the melodrama, but it is the easiest way I can think of to illustrate what in effect happens in photography when you close down or open the aperture of your camera lens. Just as squinting your eyes made the stranger on the beach and the surroundings more clearly defined, your principle subject and the area in front of and behind it becomes more clearly focused as you adjust the lens to a smaller opening. Conversely, in darkness, it takes time for your eyes to adjust (for the pupils to dilate) and then, your eyes will only focus on one particular object
This range of sharpness in front of and behind your primary subject is called the "depth of field". At a large opening, the depth of field is very shallow...only those things that are directly on the plane of focus will appear to be sharp. As you close the lens down (towards f22), the area before and behind will begin to appear clearer. The distance your subject is away from the film plane also affects the depth of field. The further away your lens is focused, the greater the depth of field. The closer you are to your subject, the more narrow the depth of field. This is why in close up pictures of coins, it is often only the very centre portion of the coin that appears sharp and the edges are blurred. The depth of field will also vary from one focal length of lens to another. The shorter the focal length of the lens (wider angle), the greater degree of depth of field results. Going the other way, the longer the lens (telephoto), the more shallow the depth of field or range of apparent sharpness. The type of film you are using can also have an effect on the depth of field in the final picture. The higher the speed of film you use, the greater the grain. Because of this graininess, the image will appear to lose sharpness. Since depth of field only relates to apparent sharpness, the grain
will make the softer areas of sharpness appear to be out of focus. For the same reasons as above, the degree of enlargement of the image effects the sharpness of the overall image and the loss of definition will be more readily apparent in the marginal areas of the depth of field.
10.01 Hyperfocal Distance Once you reach infinity, everything appears to be sharp. After all, infinity by definition is infinite or without end. Realizing this little photographic truism can benefit you greatly as a photographer. We know that the depth of field expands both in front of, and behind your subject. Therefore, if your lens is focused at infinity, the depth of field normally formed behind the subject is wasted. On most lenses, there is a depth of field scale that will give you the range of acceptable sharpness for each f-stop. If you are using f16 on a 55mm lens focused at infinity, the depth of field scale on the lens shows that everything from about 20' to infinity will be sharp. Although your principal subject may be at infinity, you can adjust the distance range on the lens to the 20' setting and now everything from 10' to infinity will be in focus. Note: after you have changed the distance setting and then look through the viewfinder, your subject may not appear sharp-(do not adjust it). This is because on most cameras, the lens is at maximum aperture until the instant of exposure. Therefore visually, the depth of field is only at the specific distance where the lens is focused. The hyperfocal distance is the distance setting where the focus point of the lens will yield sharpness from a minimum distance to infinity as determined by the shooting aperture. In the example stated above, the hyperfocal distance is 20'. 10.02 Selective focus Another use of this phenomenon of lens apertures and depth of field is to select an f-stop to creatively isolate your subject by keeping the areas most important to your composition in focus while allowing the foreground and background to remain out of focus. This technique is called selective focusing.
Selective Focus Background is out of focus
Heron is sharp
Foreground grass & brush are out of focus Let's assume you wish to take a shot of someone in a crowd of people on the street. You have the 55mm lens on your camera and no time to change lenses. When you meter, you get a reading of 1/60" at f8. You focus and your subject is 10' away. Ten feet at f8, according to the depth of field scale on your lens, will give a range of sharpness of about 8.5' to 13'. In other words, most of the crowd will appear sharp. By opening up the lens to f4, your depth of field will be reduced to 9.5' to 11'. This means that anyone standing about a foot behind your subject or six inches in front them will be out of focus as compared to your subject. The angle of the lens is such that you will still be able to tell that there was a crowd of people around them, however, the main subject will be selectively isolated and sharp within the shot.
11.00 FILTERS 11.01 Protection The two filters recommended for use on every lens are the 1A Skylight or the UV Ultra-violet filter. The 1A Skylight filter was originally developed in the fifties. Its pink color was used to correct for the excessively blue sensitivity of color films of that time. Today's film technology doesn't require color correction for outdoor pictures. In it's place, the UV Ultra-violet is favored for use with today's lenses and film. In addition to protecting the optics, this filter helps reduce the effects of UV light improving sharpness and color fidelity. 11.02 Polarizer: More than a pane in the glass When shooting through water, glass, or other shiny surfaces, your subject may be obliterated by reflections. In order to eliminate unwanted reflections, you can use a polarizing filter. The Polarizer consists of two dark lenses designed to align the rays of light uniformly such that the one layer of glass in the filter will reduce or eliminate the reflection. The Polarizing filter â€œstraightensâ€? the light rays of both your subject and the reflective surface. When the out element of the filter is turned, it reduces, if not eliminates, the reflection. Another very popular use for a Polarizer is to build contrast between clouds and blue sky. Whenever you see a photograph of brilliantly white clouds contrasted with a deep blue sky, the odds are very high that the effect is the result of a Polarizing filter being used on the lens.
11.03 Practical filters for color Color film by definition will show the effect of placing a color filter on the lens. That is to say that if you put a red filter on your lens, the resultant photograph will be red in color. Naturally then, unless it is a specific desired effect, it is generally inadvisable to put colored filters on your lenses. There are a number of filters that are designed to correct the color balance of the scene due to various lighting conditions. In order to understand the need for these correction filters, it is first necessary to have a fundamental understanding of light (color temperature) and film's color balance. 11.04 Color Temperature Throughout the day, when the sun is higher in the sky, colors are natural. By evening, the sun's light is warmer adding a yellow-orange color to everything. Similarly at dawn, the pastel shades cast by the rising sun are also warm but softer in tone. These changes in the color of light are obvious and we are used to them. Similarly, when we move from daylight outdoors into the home or office, the light changes substantially in color. Because this change is constant and predictable, our brains make allowances for the difference in the color of light and it is less noticeable visually. However, film doesn't have the ability to interpret color and then adjust for it. As a result, these variances in color temperature dramatically change the appearance of the photographic image. Color temperature is measured in degrees Kelvin. The scale of light's color temperature ranges from red at approximately 1,000 degrees K. to blue (15,000 degrees K.) that is bright, midday sunshine in winter. Normal daylight, which film is designed to reproduce natural color, occurs at 5000 to 5500 degrees Kelvin.
11.05 Color Temperature Correcting Filters The following chart identifies a number of specific lighting conditions, their color temperature, and the correction filter, which can be used to correct for the color imbalance. Color temp. 15,000 K 12,000 K 10,000 K 9,000 K 8,000 K 7,500 K 6,500 K 6,000 K
Light source Correction
Light from north sky (15,000-20,000 K) Clear blue sky in shadow (12,000 K+) Sky-hazy blue, high altitude (9,000 K) Deep shade, clouds (8,000 K) Skylight overcast Sky-medium overcast (6,800 K) Sky-heavy overcast Electronic flash (6,000 K) Daylight color film standard and blue flashbulbs (5,500 K) Noon sun (5,400 K) Theatrical arc lights and direct sunlight (5,000 K) Blue photo floodlamps (4,800 K) Early AM and late PM sun
Clear (aluminum) flashbulbs (3,800 K) Photo floodlamps, Type A color film standard (3,400 K) Professional photolamps, Type B color film standard (3,200 K) 200 W household light bulb (3,000 K) 100 W household light bulb (2,900 K)
80A (blue) 80B (blue)
40 W household light bulb (2,650 K) 2,000 K Candlelight (1,900 K) Setting Sun (1,500 - 2,000 K) 1,000 K
In addition to the above lighting conditions, frequently pictures need to be taken in an office or factory that is illuminated by fluorescent lighting. These lights cast a yellow green color on your subject. In order to correct for fluorescent lighting, there are two common filters that are used. These are the FLW filter for use under warm fluorescent lights, and the FLD filter for use with daylight type fluorescent lights. 11.06 Filters for Black & White When using filters and color film, the resultant effect is obvious, you see it right there in the viewfinder. When using filters for black & white photography, the effect is less predictable without an understanding of how they work. Left unfiltered, black & white film tends to reproduce a scene in a relatively smooth continuous series of tones ranging from black shadows, through gray mid-tones and on to white highlights. Although accurate representations of the scene, most black and white pictures taken without filters lack luster. They are flat in appearance. The most popular of black & white filters are designed to increase the contrast by compressing the range of tones between black & white. The most popular filter is the Yellow, which is commonly referred to as Y2 or K2 filter. This filter absorbs the blue light part of the spectrum helping to give skies better definition and slightly enhancing the overall contrast of the scene reducing the number of gray tones and giving more emphasis to the blacks and whites. In landscape photography, a green filter is often used to render green foliage lighter and red tones darker. Again the desired effect is to increase the contrast in the primary interest area of the scene by giving greater separation in the green tonal values. A red filter will boost the contrast as much as possible. The blue in the sky will turn almost black causing the white of the clouds to seemingly jump off the paper.
11.07 Special Effects Today, your choices in special effects filters are virtually limited only by your imagination. Special effects can be broken down into two sub-classifications, scientific and artistic. Scientific filters are designed for very specific applications. By example, there are a series of filters made for Infrared photography. These filters are made to exacting tolerances to only permit certain wave lengths of light to get through for exposure on the film. There are also filters made for transmitting narrow bandwidths of ultra-violet light. Such filters are generally used in scientific and/or forensic police investigation work. In artistic filters, there is an incredibly wide array of colors, gradients, and effects available. Companies like Cokin of Paris, France manufacture over 80 different filters for use with black & white or color film. In colors, they range from the conventional yellows, reds, and blues to tobacco, sepia, to multi-colors (from one filter). In effects, there are the normal polarizing filters to speed filters that blur one part of the image to create a sense of speed to the photograph. 11.07 Special Effects (cont=d) In addition, there are diffusion filters that soften the overall sharpness of a picture giving almost a paintbrush type effect. There are also spot-diffusers that leave the centre of the picture sharp but then the image blurs towards the outside edges of the frame. A lot of people have expanded their fun in photography by creating their own special effects filters. The easiest and often most rewarding effect is to take an old or used UV or Skylight filter that will fit your lens, and smear petroleum jelly on the glass leaving just a small area of the centre clear. This will give you a spot diffusion filter. If you want more diffusion, simply smear on more jelly. Want to change the effect a bit? Try smearing it in parallel lines instead of circular.
A cross screen effect (star like) can be achieved by simply holding a piece of ordinary screen material over the filter on the lens. Presto! Every highlight will appear as a star. If you want more aspects to the stars, try a piece of nylon stretched over the filter in place of the screening material. How about trying colored cellophane? What about trying a piece that is smooth and then one that is crumpled?
12.00 FLASH PHOTOGRAPHY Inside under artificial light and outdoors in low light are obvious opportunities to use flash. Unfortunately, in most pictures where flash is used, it is often disappointingly obvious. In the picture of the family dinner, the people nearest the camera are bleached out and dad carving the turkey at the other end of the table is lost in the shadows. To get more natural looking flash pictures it is necessary to understand something of the character, limitations and flexibility of using flash properly. 12.01 Inverse square law "Light diminishes at the square of the distance from the light source to the subject." If you place a light bulb inside a box with only a small pinhole to emit light, you get a fairly well defined beam of light. By holding up a piece of cardboard 12" away from the box, the beam casts a circle of light approximately 9" diameter covering an area of 57 square inches. When you increase the distance between the light source and the board to 24", the size of the circle increases to about 18". In addition to traveling twice as far, the light is also being dispersed over a much larger area. In this example, the area covered is 227 square inches or four times larger. Therefore, the required change in exposure is four times, or 2 stops greater. If the distance between the light source and the subject (the board) is quadrupled (i.e. from 12" to 48"), then the intensity of light at the new distance is onesixteenth requiring a change in exposure of four stops.
12.02 Flash synchronization One of the most common failures in flash pictures results from failing to select a correct shutter speed when using flash. Particularly with older cameras, it is imperative to make certain that you use a shutter speed that will "synchronize" the firing of the shutter at the time the flash is fired. The end result is that a portion of the picture is properly exposure and the balance is very dark or black. The black bar will vary in size depending upon the shutter speed that was selected. It may also run across the picture or from top to bottom depending on the type of shutter the camera has. With focal plane shuttered, single lens reflex cameras the shutter speed is determined by the distance between when the first curtain enters the image plane and the second curtain begins to follow. The time lag between the two curtains has to be long enough to leave the entire image plane fully open when the flash is fired. Generally this occurs at 1/125" (or longer) duration. As a result, when the flash fires, exposure across the entire image area. When a shutter speed greater than the synchronization speed is selected, only a portion of the image will be exposed. At 1/500", only one-half of the image will be exposed at 1/1000", less than one quarter; and at 1/2,000, one-eighth.
12.03 Red Eye Red-eye is the result of the light of a flash reflecting off the retina of the subject's eyes and being recorded on film. It is scientific fact that: 1) light travels in straight lines 2) the angle of reflection is equal to the angle of incidence. Consequently, if the flash is located anywhere near to the lens of the camera, the reflected light will necessarily be recorded on the film. Since the retina of the eye is composed of many blood vessels, the reflected light is red. The only way to effectively eliminate the occurrence of red-eye is to change the angle of incidence of between the flash and the subject's eyes. In other words, get the flash off of the camera. When the flash fires, the reflection of the light from the retinas will be away from the film and therefore not recorded on film. With cameras that do not have detachable flashes, here are a couple of techniques that can help to reduce red-eye: 1) turn on as many lights in the room as possible. This will help contract the pupils of their eyes and therefore reduce the amount of visible reflection. 2) have your subject sit near a lamp or window, again this will help contract the pupils. 3) have your subject look away slightly from the camera. This will change the angle of reflection so that the â€œredâ€? light is not bouncing back into the camera lens.
12.04 Synchro-sun Syncro-sun is another term used for taking pictures with flash outdoors and is essentially â€œfill flashâ€? photography. The significant difference relates to the actual matching of the flash output to the amount of sunlight falling upon the scene. Fill flash is the term used under any lighting condition (natural or artificial) where the purpose of the flash is to simply lighten the shadows. To calculate your exposure, take a "normal" meter reading, and then match the output of the flash to deliver approximately one f-stop less light than the normal daylight exposure. This will create a "normal" and balanced exposure with a lighting ratio of 1:3. 12.05 Bounce flash Photographing metallic or glass surfaces will commonly result in reflections or "hot spots" where very little or virtually no detail will be recorded on the film. Rather than firing the flash directly at the object, a common practice is to use "bounce" flash. This produces a more even and softer quality of light minimizing reflections.
Things to remember for bounce flash: 1) the light falling on the object being photographed will assume the same color as the surface that the light is being reflected off. So, make certain that the reflective surface you are using is white. 2) determination of the correct subject to flash distance must account for the distance to the reflective surface plus the distance the light then has to travel from the reflector to the subject. 3) In addition, it is necessary to make an allowance in exposure for the amount of light that will be absorbed by the reflector. Typically, this is about one and one-half stop to two full stops. 12.08 Multiple Light Sources One of the most commonly misused techniques by advanced amateurs and professionals alike is the use of multiple flashes. There are some circumstances when one flash simply can’t illuminate the entire scene evenly. The difficulty most people run into is that with the addition of each new light source, you have the potential to create crossing shadows. The end result can wind up looking very unnatural. The most critical element when using any form of artificial light is to keep in mind that overall effect of what you are trying to do is recreate lighting just as if you were shooting outdoors. There is only one sun in the sky, so it should appear that there was only one light source used to expose the picture. Any and all other lights are used to compliment the “main” light-not compete with it.
The most effective, technique to create accent lighting and/or to illuminate shadows is to use a reflector. Place the reflector close enough to your subject so that the light bouncing of it will add some light to the shaded areas. Your flash or â€œmainâ€? light still determines the exposure as the reflected light has to be less intense and therefore will not alter the exposure settings. There are commercially made reflectors you can buy, or you can use a white shirt or piece of bristle board as a reflector. Tinfoil on a piece of cardboard also makes an excellent reflector. Having your subject sit or stand close to a white wall will also help open up any shadow areas created by the main light. 12.06 Apertures as distances One of the more time consuming elements of achieving a consistent and correct lighting ratio is determining the correct distance for a second light source. An easy way to make the positioning of the lights to get the desired effect is to equate the distance between the main and the fill lights to correspond to aperture settings. By example, if you set your "main" light at 8', then to achieve a 3:1 ration (or one-stop difference) would be to place the second, identical, light at 11'. For a 4:1 ratio, you need a two-stop difference, therefore you could either move the fill light back to 16', or move the "main" light to 5.6'.
13.00 FROM SHOE BOXES TO FRAMES 13.01 Storage & care of your images The most important factors in considering how to store your prints and negatives are UV light, heat and humidity. These are film's three greatest enemies. UV light such as fluorescent light that has a high UV content will attract the dye of a picture or film. Over time, the picture will begin to look yellow-green in color as the cyan dye layer is dissolved. For this reason, when a picture is being framed and hung on a wall, it should preferably be kept in a place out of direct sunlight and not in fluorescent light. Humidity is the breeding ground for mold and fungus. Keeping your film and pictures in a cool, dry place is the best ounce of prevention. As funny as it may seem, the good old shoebox seems to make a wonderful container for storing film which is compact in size, easy to keep organized and will often find a convenient home in a bedroom closet where there is little or no moisture. If caught early enough, some fungus and mold can be removed by soaking the film in water followed by a stabilizing bath. However, this is a potentially harmful process and really should only be performed by an expert. Left too long, the mold or fungus will actually adhere to the dyes or halides in the film and become impossible to remove. Subjecting any film to heat is potentially damaging. Raw film (unprocessed) is light sensitive, after all this the whole reason why photography works as we know it. The silver halides react to light energy to give exposure. It is the "energy" part that is important. Like light, heat is an energy source and has the potential to nucleate (expose) the silver halide. For this reason, it is NEVER a good idea to leave film in your car and particularly the trunk of the car. The temperature on a hot day can easily exceed 200 degrees Fahrenheit, which will ruin the film.
Another form of energy that we all need to be aware of is x-ray. Although airport x-ray has been around for many years, and most of the units are safe, it is important to be mindful of the fact that it can be damaging particularly to higher speed films. It isn't only the risk of one malfunctioning machine that may cause a problem. The effects of x-ray are cumulative. Every time a film passes through an x-ray machine, there is a virtually invisible exposure recorded by the film. If you are traveling non-stop to Florida, then there is very little risk of the x-ray becoming visible. However, if you are traveling to the Middle East with a number of stops and/or transfer of planes en route, then each stop could result in a slightly higher cumulative exposure. Eventually, the visible threshold will be surpassed and the shadow from the x-ray will be seen in your pictures. More importantly, exposed but unprocessed film is at significantly greater risk as the silver halide has already recorded the image and is therefore very sensitive to any additional exposure. In most airports, a little pre-planning and simple courtesy will usually go a long way to reduce if not eliminate the risk of x-ray exposure. Carrying your film, out of its boxes, in a clear zip lock type bag makes for easy handling. Plan to be at the airport and clear the gates well ahead of flight time so that you can approach the security station when it is not as busy. Normally, if you simply explain that you would like the film hand inspected and sending your camera equipment through the machine will be accommodated by the security personnel. Even if it doesn't work at every airport, at least each time the film misses the x-ray, it reduces the cumulative effect of potential exposure.
13.02 Albums do and albums don't After investing so much time, energy, and money into capturing those precious moments, it is amazing how many people simply throw their pictures into a drawer and the negatives go anywhere. Sooner or later, there comes a need to reproduce one or more of those treasured images for a gift or celebration. Although there are a number of ways to copy an image either photographically or digitally, the original negative still offers the best result at the most affordable cost. Taking a little bit of time and investing a little in a good album invariably saves time and money in the long run. The single most important concern in choosing an album is whether or not it will protect your pictures or accelerate the destruction of your images. There are a wide variety of albums on the market in a broad range of prices. It is important that the pages within the album be of archival quality. In old-fashioned style paper albums, the paper needs to be "acid free". Most of today's paper is not. Unfortunately, over time, the acids in the paper may leech out and attack the dyes and/or silver in the image. Acid free paper is expensive to manufacture and as a result, these types of albums tend to be pricey. However, the benefit to using them is that when the album is put together, it makes a very attractive presentation piece and because the pictures are left open in the album, there is less risk of their deteriorating. A low cost alternative to paper albums are the plastic sheets with pockets for each individual picture. Although frequently rated as "archival", this generally refers to the fact that the plastics used do not emit PCV gasses that will attack the pictures. What it doesn't address is the fact that when the album is closed, the picture is sealed in plastic. As a result, if there are any changes in humidity, the pages and album don't breathe and the humidity can be trapped on the picture that in time can cause several problems with the pictures sticking to the plastic material and/or humidity actually beginning to attack the dye in the photograph.
In my view, the one type of album that should be avoided at all costs is the sticky cover sheet type. The picture emulsion needs to be able to breathe and expand and contract with changes in climatic conditions. The type of pages where you lay out the pictures in patterns or combined with newspaper clippings and then press down the clear plastic overlay is very dangerous for the well being of photo images. 13.03 Displaying Images Every once in a while we capture that one in a million image that goes well beyond a simple snapshot, it is suitable for framing. You are now entering the world of decorating with photographic art. There a great many books written on the subject of framing and hanging artwork, so it's not the intention of this article to cover that, which is so well presented by professionals in the decorating field. However there are some considerations regarding photography specifically which need to be addressed. Most notably among these are the concerns relating to the environment where the photograph is going to be hung. As mentioned earlier, direct exposure to UV light should be avoided as much as possible. Where some sunlight or fluorescent light exposure is unavoidable, the photo should be covered with some form of UV filtration. There are UV inhibitors available in sheet and/or spray on form for this purpose. The concern in applying sprays directly to a photograph is that they may trap humidity on the print surface that will, over time, attack the photographic dyes. The print emulsion needs room to breathe. For this reason, it is advisable to matte and frame the photo behind glass. A cardboard matte, in addition to providing an attractive accent to show off your work, will also provide an air space between the photo and the glass in the frame.
It is also important to use only acid free mounting materials for both the matte and the mounting board that the picture is being affixed to. When hanging the picture in a newly decorated room, wait at least a week or longer if the room has been freshly painted. The fumes from fresh paint can also be damaging to your image (color or black & white).
Published on May 25, 2010
Published on May 25, 2010
A brief introduction to understanding and improving your photography skills. From understanding how the camera works to techniquies that wi...