Best camera for vision tracking

[nathan_hui]

OK. So this is kind of a question of math and goals. I ask about the resolution because it affects the pixel density at range. You should also consider the FOV (field of view) - that will affect what you can see, thus also affecting the effective pixel density of your target. 1080p usually means a 2.1 megapixel image (1920 x 1080 pixels). FOV is affected by your choice of lenses. If you have a small FOV, you can only see a small section of the field at any given moment, but you'll have excellent resolution for that section of field. If you have a large FOV, you'll be able to see more of the field in any given frame, but with less detail.

According to Logitech forums, FOV for the C516 is 74 degrees. That means +/-37 degrees (diagonal), or +/- 33.3 degrees in the horizontal. At 54 feet, a 71 foot wide target will fill the entire image (i.e. 27 pixels per foot, or 2.25 pixels per inch). With the usual 4 inch target, that means a nominal 9 pixel width (more likely 7-8 due to lens distortion and slight offsets)

Also, beware of your so-called 1080p resolution capability. According to the Logitech website, the camera will do video capture in 1080p, and video calling (i.e. real-time streaming of video) at 720p. You're probably not going to get the 1080p resolution without some really interesting tinkering. I suspect this is due to the datalink bottleneck (USB 2.0 isn't that fast, and 1080p video can get pretty big).

So realistically, you'll get 1.5 pixels per inch, or 6 pixel width on the reflective strip (720p imagery). I guess in this sense, the camera is ok. Question is, does your software interfacing work? Can you reliably get images in a timely fashion? If you can't, you've wasted either $135 or $50, depending on which device you decide failed.