Superb Professional Camera Using CMOS Chip
by John Henshall
The Sound Vision CMOS-PRO camera is an unprepossessing black box which produces 960 x 800 pixel images. But don't let these facts fool you: this camera produces images by which others - even those with a much higher nominal specification - should be judged.
Sound Vision is headed up by Bob Caspe, the man who founded Leaf and was responsible for the Leaf Digital Camera Back. Introduced at Photokina in 1992, the Leaf has set benchmark standards in high-end digital capture. Caspe sold Leaf to Scitex but it is clear that he has applied much of the experience gained with Leaf to his new CMOS-PRO camera.
Until now, all professional digital cameras - and flatbed scanners - have used CCDs. This is the first professional camera - and only the second digital camera of any kind - to use a CMOS chip. CMOS stands for Complementary Metal Oxide Semiconductor. The 10.8 x 8.64 mm sensor is made in the UK. The camera is made in the US.
The black box camera measures 5.5 x 4 x 1.75 inches (14 x 10 x 4.4 cm). It has no viewfinder and no operational controls. There is a C-mount lens thread on the front and tripod bushes top and bottom. On one end are two SCSI-2 connectors together with SCSI ID and termination switches (or parallel port for the PC version), a flash sync connector and 6VDC power in socket. That's all.
Almost any C-mount lens may be used. C-mount was originally used for 16mm motion picture cameras and I still have some of the superb Paillard-Bolex Switar range (made in the late 1950s), which I used for the accompanying pictures. C-mount is now used for CCTV, so a wide range of lenses is available, including fisheyes, though not all these can be used because lens elements projecting behind the lens mount would interfere with the behind the lens filter. Extension tubes, macro and microscope adapters are also available - as are adapters for 35mm SLR lenses.
The camera is set up and operated from a computer - I find my Macintosh PowerBook G3 convenient, though even a crude (wire frame?) viewfinder would be useful for initial 'aiming'. The software is an Adobe Photoshop plug-in. The interface has two video preview modes, to allow framing, a zoomed-in mode and sharpness bar for focusing and exposure control for video and continuous lighting shots. A 'final image' mode enables selection of monochrome (single exposure) or colour (three exposure), flash or continuous lighting, a histogram with adjustment for black and white points, plus neutral to set a colour balance using a grey card - I used the cricket pads in the screen grab. Clicking 'Upload Image' acquires the image into Adobe Photoshop interpolated to 200% - 1920 x 1600 pixels. Clicking 'Save Image' saves the image as a natural resolution 960 x 800 pixel TIFF file.
A colour exposure using flash takes approximately 23.5 seconds from clicking the 'Take Picture' button. The first - red - exposure occurs after four and a half seconds, followed by the green exposure seven seconds later, followed by blue after a further seven seconds. Then it takes a further five seconds for the three exposures to be processed as one and to be displayed on the computer monitor. This means that the camera cannot be used for photographing 'live' subjects - except in monochrome.
Pixel interpolation, mediocre lens quality, 'noise' in the signal and the substantial compression of images for storage on limited capacity removable media are just some of the factors which contribute to major reductions in final image quality for 'cheap' single exposure camera using similar pixel-count sensors.
Each of the CMOS-PRO's pixels is exposed three times, through a rotating filter wheel inside the camera, so three times more real picture information is captured. The images which this camera produces are of exceptionally high quality. The captured information is pure, clean and free of artifacts. These are by far the finest quality images at this resolution which I have ever had the pleasure of seeing. In short, they are stunning. Astounded by their purity, I made some 10 x 8 inch dye sublimation prints. Pure clean images also tend to interpolate up well and, sure enough, the images are even acceptable at this size. Can this be possible from a 960 x 800 pixel image? It is. Sizes up to 6 x 5 inches in a magazine should be no problem. And that covers most images.
Size - when it comes to pixel count - clearly is not everything. Unfortunately we have been conditioned into accepting much lower quality. Every digital camera designer, manufacturer, salesman and photographer should be compelled to study the excellence of CMOS-PRO pictures and use them as a benchmark.
Finally, cost. Of course we expect to pay for state-of-the-art quality. So how about US$1,995 - which should convert to about £1,350 allowing for import costs? And that includes 12.5 and 50 mm lenses.
For a modest outlay, the Sound Vision CMOS-PRO will set you on precisely the right learning curve and continue to be a useful, productive and profitable instrument long after you make your larger investment. If you've been considering dipping your toe into the murky waters of digital acquisition, but are worried about justifying the outlay, the CMOS-PRO could be just the answer to your ROI prayers.
Sound Vision may be contacted at http://www.soundvisioninc.com
This article first appeared in "John Henshall's Chip Shop", September 1998.