Below is a picture the tested CCTV camera took of itself;
you will notice some "field distortion" in the image.
Continuing progress in solid-state imaging technology and increasing economies of scale are putting downward pressure on the price of video cameras, such as used by some of the visually impaired in conjunction with video monitors as closed-circuit television electronic magnifiers. We discuss a specific technology example in a (USA) National Federation of the Blind mailing-list post of January 2000 here. (Be aware that product features and prices change over time before buying any equipment.)
I regret to say that Yahoo! Geocities blocks DIRECT access to the image files pointed to in the NFB mailing-list post here to which the post above refers. So instead, you can look at these images at the bottom of the present page.
In January 2002, TechTV's program The Screen Savers had the vision-impaired manager of a firm selling CCTV-based assistive products demo some of them. Find the show notes here. The firm, identified as Allied Technologies, makes some interesting remarks on their CCTV primer Web page here. They say:
"...It is natural for a low vision person to get as close as possible to what they're trying to see. Put a video monitor of a CCTV in front of them and they will invariably position their head 6" or less from it. If they are looking at a positive (white background) image, their eyes are being bombarded by bright light. Just like looking directly into a light bulb at close range. It doesn't take very long for this to become uncomfortable for most people.
"In our experience at least 80% of low vision people who obtain CCTVs use them in the negative (dark background) mode for reading...
"With an electronically processed magnified image it is possible to custom select the foreground and background colors. For example, yellow print on a green background. We have found that many people who suffer from Retinitis Pigmentosa, Diabetic Retinopathy and other afflictions of the retina find this to be the best combination for them to read comfortably..."
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