HDRI Handbook 2 Sample Tutorial

4.4.2

4.4.2 Rear Window of Room 822 (with PhotoEngine & Photoshop) Let’s move on to a real classic: the beauty shot of an interior with a window to the outside. What most people regard as a worst-case scenario is the daily bread for professional real-estate photographers. And just as Michael James revealed in the interview earlier, HDR techniques come in very handy here.

The tough question is, How far can you take the look and still stay true to the location? My particular example, room 822 of the Chelsea Hotel, illustrates this problem pretty well. It is a moody, dark room with orange walls and warm interior lighting, which stands in strong contrast to the cold evening light coming through the windows. There is an opulence of playful detail in the furniture, in plainspeak referred to as kitsch, paired with the very expensive kind of grungy run-down charm. It’s sort of the architectural equivalent of an haute couture punkrock T-shirt. The challenge is now to strike a bal-

ance between compressing the dynamic range, recovering details, maintaining the mood, and exposing that certain glam rock flair.

This tutorial will introduce you to Oloneo PhotoEngine and a useful generic trick for problem solving in Photoshop. The image happens be to a panorama again; that’s why it shows such an unusual wide angle. The left and right sides of the image are actually opposite walls of the room. Workflow-wise, the image went through the same processing steps as the shot from the last tutorial. Multiple bracketing sequences were batch-merged to HDR in Photomatix and then stitched together in PTGui. This image uses a Vedutismo projection, which is a special panoramic perspective inspired by seventeenth century paintings, and has the special property of keeping architectural lines straight.

If that spurs your interest, definitely check out Chapter 6. For now it shouldn’t really matter where the HDR comes from.

Figure 4-57: Room 822 of the Chelsea Hotel, New York. Madonna lived here before she got famous. Avid fans might recognize the location from her book Sex.

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y Part A: Tonemapping with PhotoEngine

Figure 4-58: Gentlemen, start your PhotoEngines! That’s what the image initially looks like.

PhotoEngine is only available for Windows. I’m running it on a virtual PC under VMware Fusion, and it works just fine without any performance penalties. So, having a Mac system is no excuse to sit this tutorial out. Go ahead and install the demo version from the DVD! 1 Load Chelsea_Room822.exr from the DVD into PhotoEngine. You can double-click its thumbnail in PhotoEngine’s integrated image browser or just drag and drop it from Windows Explorer into the program. Similar to Photomatix, PhotoEngine has a whole lot of controls that are all interconnected in some way. But don’t worry; they are sorted by importance from top to bottom (roughly), and we really only need the first part.

Figure 4-59: Turn off Auto-Exposure and Auto-Contrast. Then use TM Strength and Exposure to reduce the overall dynamic range.

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2 Auto-Exposure and Auto-Contrast: These two check boxes are responsible for keeping exposure and contrast steady and optimized.

Sometimes this may be useful, but more often they add to the confusion of everything being

4.4.2

interconnected. Besides, we will optimize contrast later in Photoshop anyway. The first goal is, once again, to create a slightly flat image in which neither highlights nor shadows are clipped.

Instead, you have to watch out for clipping.

In this image the critical areas are the window reflections on the floor. A Detail Strength setting of 90 is about the highest you can go before all the nice scratches on the hardwood floor are blown out.

3 TM Strength and Exposure: Both sliders are now used together to reduce the overall dynamic range. You will notice that TM Strength pushes brightness from the bottom up, which means it brightens up the entire interior, affecting the shadows most. It also has an effect on the window, even if ever so slightly. Lower the Exposure value to keep the window steady in brightness.

For this image, a TM Strength setting of 55 and an Exposure setting of −1 seem to be a good balance between indoor and outdoor.

4 Detail Strength finally adds some pop to the image. Now we’re talking! This is the magic slider responsible for local contrast boosts, and it allows a pretty massive range of adjustment.

Detail Strength goes all the way to 300, just like the Detail slider in Photoshop’s Local Adaptation dialog box. But the difference is that this one is extremely resistant to halo artifacts.

Before

Figure 4-60: Use Detail Strength to boost local contrasts.

After

Figure 4-61: Detail Strength is mighty powerful and very halo resistant. Watch out for clipped highlights instead!

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Before

After

Figure 4-62: Smooth gradients can become posterized by this detail boost.

A good way to balance such finer nuances is to adjust contradicting sliders in pairs.

Size: 10

Threshold: 200

Size: 100

Threshold: 200

Size: 200

Threshold: 200

Size: 10

Threshold: 100

Size: 100

Threshold: 100

Size: 200

Threshold: 100

Figure 4-63: Switch to the Advanced Local Tone Mapper option for the complete set of detail controls.

Detail Threshold

Edge Sharpen 0

Size: 10

Threshold: 0

Size: 100

Threshold: 0

Size: 200

Threshold: 0

Detail Size

Figure 4-64: The difference between Detail Size and Detail Threshold becomes more clear when you temporarily raise Detail Strength to full 300.

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Edge Sharpen 100

Edge Sharpen 200

Figure 4-65: Edge Sharpen allows fine-tuning of halo artifacts that appear around extra-bright light sources.

5 Balancing Contrasts: Clipping can also happen in individual color channels, which becomes most obvious when smooth gradients start to posterize. To keep Detail Strength as high as possible, we have to inconspicuously lower the global contrast further. It’s a balancing act.

That’s where the opulent amount of seemingly contradicting sliders comes in handy. My favorite method is to adjust them in pairs. For this image, it turns out that raising Brightness to 50 and lowering Fine Exposure to −0.65 smoothes out the lamp shine on the wall but keeps everything else.

It takes a bit of dabbling with the good old trial-and-error method, but thankfully PhotoEngine’s real-time feedback makes that process

4.4.2

Figure 4-66: That’s a keeper!

Save the image as a 16-bit TIFF. Everything is tuned in just right. Everything except for white balance…

fairly painless. Don’t be afraid to make mistakes; you can always go back in the timeline to a previous state.

6 Advanced detail controls: So far we used only the basic controls that are also available in PhotoEngine’s little sister application HDRengine.

Now it’s about time to switch to the Advanced Local Tone Mapper option (with the drop-down menu on top of the slider list). This is the real deal! Now we have all the knobs for fine detail adjustments we could ever wish for.

Detail Size defines what is considered boostworthy detail by sheer size. It’s similar to Photomatix’s Lighting Adjustments feature, except that the adjustment is isolated from overall contrast (and therefore has a more subliminal effect). Detail Threshold, however, adds another dimension to the detail selection problem. It separates local neighborhoods by luminance so it can better account for sudden shifts in brightness. The hard window frame is a perfect example.

Granted, the visual difference between these two parameters is very subtle. Browse back to section 4.1.2 and look at the underlying separation mask again, and it may make some sense.

Detail Size is like the blur radius of that separation mask, and Detail Threshold keeps the blur

from creeping over hard edges. Together they work as a pair. At first glance they seem to contradict each other, but when you get to the bottom of it, they give you a lot of control over the result. Finding the right balance is easier when you temporarily push Detail Strength all the way up, so the effect is more exaggerated.

For this image I settle with a higher Detail Size value (to protect long, smooth gradients on the walls) and a lower Detail Threshold value (to suppress halos around the window). With that new, refined definition of what “detail” actually means, I can increase Detail Strength to 120.

Edge Sharpen is the third parameter, and this one is really for obsessive fine-tuning. You have to zoom in to a very high-contrast edge to see any effect at all. When worked right, Edge Sharpen can remove halo artifacts, or at least make them more unobtrusive.

7 Save as a 16-bit TIFF. All the tonal values are now distributed perfectly. There’s no significant clipping, all gradients on the walls are smooth, and details are rendered with good clarity but without exaggeration.

However, we’re not quite done yet. The superwarm light inside is a bit too much. It looks nice on the walls, but the fireplace is in fact built out of white marble, which is hard to believe given

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Figure 4-67: Use the color picker to sample the white balance from a white object inside the room.

Figure 4-68: The difference between daylight and incandescent lighting is striking.

No matter where you set the white balance, part of the image looks wrong.

that strong orange tint. (Actually, it’s fake marble—it sounded hollow when I knocked on it. But you get the idea). That’s because the white balance is currently set for the daylight coming through the window.

8 White Balance: Let’s change the white balance to the interior!

Grab the color picker (click the rightmost icon above the image) and find some white spot in the interior to sample. For example, click on the vase above the fireplace to set the white point.

Holy Moly, Batman! Stunning, isn’t it?

What we previously accepted as natural light from the outside now turns into a deep blue, like an ice-cold punch in the face. The marbleish

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fireplace looks nice, and the gold painted mirror frame can now be identified as such, but overall the room is robbed of all its mood. The problem is that the color temperatures of incandescent lighting and daylight couldn’t be farther apart.

Just for kicks, alternate between clicking on that fireplace and the bright cloud patch outside the window. The difference is striking! You can also use the color temperature slider to travel from 2500 K to 7000 K. There is no middle ground, as you will notice, only a range of foul compromises where both areas (inside and outside) look a little bit wrong.

The best we can do is to save another 16-bit TIFF for the interior colors.

4.4.2

Conflicting light colors are very common with this type of interior/exterior shot; the problem is just not always that pronounced. We’re looking at a worst-case scenario here, exaggerated by the orange walls and the extra-warm interior lighting. Every real estate shot in HDR presents a similar issue. Even if the window itself wouldn’t be visible, the mixed lighting would be just as problematic for a traditional single shot. Veteran photographers often carry a bunch of replacement light bulbs with different color temperatures, and in Hollywood movies it’s rather common to cover the windows with a color filter, maybe even block the sun and replace it with a spotlight the size of a refrigerator.

See, the tricky part is that human vision not only adapts to huge differences in brightness, it also adapts to differences in color temperature.

PhotoEngine did a really great job dealing with the first part, compressing the dynamic range in a believable way. But no HDR program can adaptively compensate for differences in color temperature. Sure, some programs offer selective adjustments (HDR Efex, SNS-HDR, Hydra),

Figure 4-69: In Hollywood, nothing is left to chance when it comes to lighting. See the resulting moonlit hallway in the background of the Chapter 2 Quiz.

but that’s when it gets very fiddly. They are hard to steer and unpredictable in the transitions between one color temperature to the other.

So ultimately, this is a universal problem.

And the only truly reliable solution is just as universal: Make two versions and blend them in Photoshop!

y Part B: Finishing in Photoshop 1 Load both images in Photoshop and copy/ paste the inside-adjusted image on top of the outside-adjusted image. It will become a perfectly fitted layer.

2 Because it’s always good to stay organized, name the layers accordingly by double-clicking their names in the Layers palette.

3 Select the top layer (Inside) and create a layer mask by clicking the third icon on the bottom of the Layers palette.

Figure 4-70: Load both images as layers, name them and create a mask for the layer on top.

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Figure 4-71: Use a large soft brush and paint on the layer mask to reveal the underlying Outside layer.

Figure 4-72: Keep on scribbling, frequently switching foreground/ background color with the X key until you have the perfect version selected for each area.

Figure 4-73: That’s what my layer mask looks like. It’s no Rembrandt, but it does the job.

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4.4.2

Figure 4-74: Finishing touches with Curves and Hue/Saturation adjustment layers.

4 Make sure the layer mask is selected and grab a large soft paint brush, about 600 pixels wide.

Set Opacity to 50 % and Flow to 40 % and enable Airbrush mode. The foreground color should be black.

5 Gently brush over the window area to make the top layer transparent, revealing the layer underneath. Whenever you want to add some of the top layer back into the mix, just press X on the keyboard. That will swap the paint brush color with white, which in the context of a layer mask means “more visible.” For example, I do like to keep a hint of the blue tint visible in the reflections on the floor, so I fine-tune the mix with a single quick stroke of white.

6 The walls actually had a nicer color in the outside-adjusted version, so keep on painting across the walls. There’s no need to be precise here because our layers already look pretty similar.

The beauty of using two premade versions is that both are plausible by themselves, and even a 50/50 mix is unlikely to introduce any new weird color transitions. So, you can’t mess up! Just keep on doodling, frequently switch paint color with the X key, and see what works best for each area.

7 Alt+click on the mask thumbnail in the Layers palette to double-check your matte. Mine ends up looking rather crude but does the job just fine.

From now on, it’s pretty much the standard procedure, as explained in the previous tutorial.

8 Fine-tune tones with a Curves layer, adding a bit of extra pop. In this case I appreciate the slight color boost that comes with it, so I do not switch it to Luminosity mode.

9 Fine-tune colors with a Hue/Saturation layer, tweaking the reds and blues to be just right.

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10 About time to get a sanity check from my trusty zone overlay. It turns out rather busy, but that is to be expected when part of the task was to expose all the gritty interior details. Most of the room is settled in the midtones, room corners recede into the darks, and the window stands out as highlight.

11 Save the master final as a PSD. Figure 4-75: The zone check is slightly busy but still very readable.

12 Flatten all layers.

13 Add some final sharpening with the Smart Sharpen filter.

14 Convert to 8-bit and save the final JPEG.

And voilà, done! Granted, the final image does have a slightly stylized look. With real estate photography, it’s always a gamble between natural appearance and glorified presentation.

The key is to show the character of a location, not just the snapshot of a room. Inside-outside shots have no appealing “natural” reference, simply because they were not possible prior to HDR, not without excessive flash lighting, which would definitely not preserve the original mood. But hey—Michael James already told you everything about this.

CHEAT SLIP Toning an interior shot with a window view

f We used PhotoEngine’s TM Strength and

f

f f f

f f f f f

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Exposure controls to regulate the overall tonal range.

Balanced local and global contrasts with Detail Strength, Fine Exposure, and Brightness.

Recovered a lot of extra detail with the Advanced Local Tone Mapping controls.

Took great care to avoid clipping and preserved smooth gradients.

Saved two versions as 16-bit TIFFs, with different settings for White Balance (daylight/tungsten).

Loaded both versions in Photoshop as layers and named them.

Used layer masking to combine the best of each.

Fine-tuned with Curves and Hue/ Saturation.

Sanity-checked using the zone overlay.

Flattened all layers and finalized with Smart Sharpen.

4.4.3

4.4.3 Urban Exploration and Grunge Looks (with HDR Efex & Photoshop) Out of all the possible ways to treat an HDR image, the full-on grunge look is certainly the most provocative. This style is all about emphasizing all the dirty little micro-details with harsh local contrast enhancements. Texture is king here; the grittier and dirtier the better. It’s probably not the best look for wedding photography because it does strange things to wrinkles and the slightest skin imperfections. Brides just don’t like the grunge treatment on their faces. Trey Ratcliff was once suspected of beating his kids when some overly empathic parents saw his experimental HDR portraits. But used in the right context, the grunge look can be rather powerful and certainly evokes strong emotions.

Urban Exploration (shortened to UrbEx) is particularly suitable because this photography niche is all about finding forgotten places and discovering beauty in decay. Things like industrial ruins, car wrecks, abandoned mansions, and run-down neighborhoods are popular places of interest. Typically these places have very little supportive light, but they are also perfectly motionless and you have all the time in the world for extra-wide bracketing. So, it’s a perfect fit for HDR shooting.

You’ll find the most rewarding subjects by going places where you’re actually not supposed to go, which is really part of the fun. As an urban explorer, you basically snoop out spots similar to the spots a graffiti artist might hope to find, except that you’re taking pictures instead of leaving them behind. In fact, you’ll often encounter the most phenomenal graffiti pieces hidden after stretches of spooky stairwells and mazed hallways, and those are always worth a tip of the hat and a subsequent photograph. Of course, I don’t endorse breaking the law or climbing over barbwire fences, and if you let yourself get caught, I don’t know you.

Figure 4-76: The question is, Do you dare go there (in terms of both location and toning style)?

Probably the most important advice in this book is to always play it safe! Don’t sneak into half-collapsed ruins wearing flip-flops! Sturdy shoes, long sleeves, and a cell phone for emergency calls are essential, and at extreme locations your equipment bag should also include gloves, a flashlight, and a hard hat. The full-on construction worker jumpsuit might look

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