Zosi – C418 Bullet

TEST

What’s in the box? Dome camera Instruction manual Drilling template Wall fixings and screws

The ZOSI ZM4182 is a very low cost “Eyeball” style analogue HD dome given an IP66 rating and IR illumination. It can provide images in four different formats to suit most analogue DVRs; CVBS (D1), AHD, TVI or CVI. It has an IR cut filter for Day / Night operation with an array of 24 infrared LEDs controlled by a front facing light sensor for night-time illumination.

Getting started

The camera requires a 12V input into its power jack and provides video output via a BNC flying socket. Current draw was found to be around 60mA in colour mode and 230mA with LEDs on, so a 12 volt PSU with sufficient headroom for startup current should be used. The two cables feed out from a joystick module that has a combined cable feeding into the camera. The joystick is used to select the video mode and to access the on-screen setup menus. A small cover is provided to protect the joystick actuator from inadvertent pressing when being installed.

The camera has a removable mounting plate with three fixing holes. This base is removed by rotating the assembly anti-clockwise against the surround when viewed from the bottom.

The joystick can be used to set the initial video output format without needing to view the video,

the default output is SD (CVBS D1) composite video. Holding the joystick to the left for around 5 seconds will set it to AHD, right selects TVI, down selects CVI and Up returns to SD. The two halves of the globe appear to form a sealed unit, there is no apparent way to open the device without damage.

ZOSI – ZM4182 AHD

Menu options

A short press on the joystick button brings up the on-screen menu list. This is simple white text with no edging so does not necessarily show up well depending on the background. The menu lists:

AE: - Brightness and Exposure mode.

AWB: - Mode – ATW, MWB, Gray World. DAY/NIGHT: - Mode – Ext, Auto, Color, B/W, Smart IR – Close, Open. IMAGE ENHANCE: - Contrast, Sharpness, Saturate, 3 DNR, 2 DNR, DWR VIDEO SETTING: - HD-CVBS, TVI, AHD, CVI. LANGUAGE: - A range of 12 languages shown. RESET: - Restore Defaults. SAVE & EXIT: - Save changes. EXIT: - Exit menus.

The OSD will clear after 30 seconds if no joystick activity. Some settings take a few seconds to settle down and may restart the camera. If making significant changes, it was found to be better to power-cycle the camera to ensure that settings had taken effect and given the right results.

Within Video Setting, if CVBS is selected the standard of PAL or NTSC can be chosen, otherwise the pixel and frame rate is shown.

Both the supplied instruction manual, and the on-line version showed a different menu structure and additional commands that were not present on the tested model. This suggests a lack of version control and it seems unlikely there is any possibility of firmware changes.

Performance

The 2MP sensor gives a 1920 x 1080 pixel display when in HD modes. While this gives reasonable image detail, the dynamic range is limited, and it does not cope so well with high contrast scenes.

TEST

The AE exposure control can be used to adjust the overall light handling though this is identified as ‘Brightness’ and is rated from 1 to 100 but appears to have 16 discrete steps within this range. This means a compromise may need to be made between daytime and night-time performance. With outdoor scenes the ‘Brightness’ could be seen to occasionally make a step change as light levels varied.

The image showed a fair amount of video noise even at high light levels, the 3 DNR setting had no noticeable impact on this and the 2 DNR setting can reduce the noise but only at the expense of loss of image detail.

In certain lighting conditions a slow flickering could be observed when in CVBS mode; there is no flicker-less mode to prevent this.

At low light the infrared LEDs are controlled by a light sensor and come on at around 15 lux, then off around 30 lux. Oddly this illumination appears to be unconnected to the camera electronics as it will still operate if the camera is set to permanent colour mode. The colour filter was seen to remove at around 5 lux and then is re-applied at levels above 40 lux.

With internal scenes there was a tendency to IR filter hunting as the camera reacts to the IR content and switches back to colour mode which then gives a low signal level and forces the switch back to monochrome with an approximately 3 second cycle. This tendency to filter hunting could lead to a reduced service life.

The illumination does work to the specified 80 feet (≈25 metres) but if used for shorter internal distances, there is a noticeable bright spot for the central part of the image.

Colour saturation appeared low when in HD mode. This could be increased by changing to the maximum manual setting of 20.

In AHD and TVI mode the camera was occasionally seen to drop video momentarily or change signal level; this was originally thought to be a noncompatibility with the test monitor, but subsequent oscilloscope tests showed that the camera’s output signal was changing. The CVBS video output waveform is a conventional 1v p:p into 75Ω with sync pulses of 345mV and 350mV chroma burst. The HD waveforms follow their respective standards for frame and line rates but were found to be defaulted to 30fps. The camera has a stated 90° field of view from a 3.6mm lens, however the measured horizontal angle was closer to 76°.

Although mentioned in the manual, there was no option to invert or mirror the camera image.

Conclusion

A very low-cost analogue HD camera that produces a 1080p colour image but will not likely provide the level of functionality and robustness required for a security or monitoring system. It lacks the base sensitivity, flexibility of settings and performance of mainstream manufacturers’ cameras.