If the manufacturers thought customers actually cared about the still photo quality of a webcam, they'd fill their web sites with samples, and provide clear specs to convince people to buy theirs instead of someone else's. Instead, they bury the details and quote phony interpolated megapixels, which means the marketing department is just painting racing stripes on a Geo Metro. I don't see this changing; if the high-end ones are going to 5MP, it's so they can do digital pan and zoom of video, not high-quality stills. Cellphone camera sensors are more likely to become useful for book-scanning, since people actually use them for stills.CCDeye wrote:Actually I only need true 2 MP photos for my needs. I can't believe, there's no web cam that can deliver this.
This sounds painful. Any film lens will have more than enough coverage for the sensor, but the focal length would have to be pretty short to be useful (~14mm, assuming a 1/3.2" sensor), and you'd need very precise positioning to get it to focus properly. Adding a close-up lens to a webcam would be a lot easier; if the problem is actually focus, a magnifying glass or old pair of reading glasses will tell you if the sensor can actually take a decent close-up still. More likely, the sensor is too noisy and low-contrast to deliver what you want.Well, I can try to disassemble an old photo camera(not even digital) and put the web camera sensor where the tape is, behind the lens. Then focus manually etc.I don't know if the sensor matrix size of the web camera is too small for the objective to project cover the entire picture.
Handwaving the numbers suggests that a +3 diopter close-up lens should bring the focus point in enough to fill the frame with a book. (that is, given a webcam with sensor width W and focal length F1 (both in millimeters) focused at infinity, adding a closeup lens with diopter D gives F2 = 1000/(1000/F1 + D), M = F2/(F1-F2), for an in-focus object size of W * M; the closer the original lens focuses, the less diopters you'll need to add)