When would you choose a CMOS over a CCD camera?

Several years ago there was a clear, visible distinction between CMOS and CCD webcams. CCD cameras were "good" and CMOS cameras were "bad". Now the line has blurred enough so that I (being a software dude) have lost track of which cameras are CCD and which are CMOS. CMOS has come a long way!

Is the field of view an issue?

The camera's field of view can definitely be an issue. Generally speaking, webcams have a rather wide field of view – the intention is that they can be placed 24" or so away from the user and you'll end up with a pleasant framing of the user's head and shoulders.

Some cameras use "software zoom" or face tracking to narrow the field of view – allowing the camera to be further away from the user. While this sounds like a nice feature, in reality, it isn't that nice. Software zooming can cause a huge loss of resolution – which results in pixilation.

Do all web cams support 30 Frames a Second?

There is substantial variation between cameras – largely dependent on the quality of capture hardware as well as the quality of the device drivers and the speed of your CPU. You'll want to make a smart choice and check out some reviews before you buy a camera.

Also, beware of OLD INVENTORY. Cameras from a few years ago can be *really bad* -- but may be placed on a shelf right next to a new model. Again, check reviews before you buy!

Finally, most people don't realize that lighting has a huge impact on frame rate. Like any camera, exposure time varies according to the lighting level. More light means a shorter exposure time – and hence, more FPS. If a camera requires 200ms to capture an image at a given lighting – it will only generate 5FPS – even it you're on the latest wiz-bang dual processor 2.7 GHz Zeon box. So... make sure you have good lighting!

One other point about lighting… The lower your lighting levels the higher the "video noise". Video noise will make your video appear grainy or washed out – which in itself is bad. But even more horrible is the fact that video noise causes major headaches for video compression algorithms – which will cause your video slow down even more. It is very hard for video compression algorithms to differentiate between "noise" and "detail". Is that sand blowing on a beach or a white wall captured by a cheap-o camera from 1991?

So, remember... Good lighting is important! (I'd like to see someone sell some sort of light-bar or light-ring which attaches itself to a CRT or flat panel display).

Can I use my Video Camera as a Web Cam? if so what are the issues I might face? How will the quality be different than my Logitech 4000 Pro?

Camcorders – DV cameras for example, have awesome image quality – especially compared to typical USB-based tethered webcams. And, many (perhaps most) DV cameras can be hooked directly to a computer using a firewire (1394) interface. You can even set your camcorder up on a small tripod on your desk and get just-the-right view of your insanely charismatic left profile. That's the good news. Now the bad news. Unfortunately, there is a "non-abundance" of applications which work with firewire cameras. vSkype, for example, doesn't support firewire cameras. We hope to fix this for vSkype very, very soon.

In the meantime, I've been told by more than one person that you can buy software on the web which will make your firewire camera appear like a webcam. Check out TrackerCam's.

Some cameras give a 320 by 240 pic size, others a 640 by 480 pic size? Which one do I want to buy? Why?

It depends on the camera. Some manufacturers will take a 320x240 image and "software zoom" it to 640x480 – just to get the checkbox on the sell sheet. Make your decision based on the actual resolution of the CCD or CMOS chip instead of featured video formats.

When I go full screen the pic is pretty ugly. What is happening here. What camera is best for Full screen?

When you go full screen, you're zooming a rather low resolution image up. Do this; take a magnifying glass and look at an image in a magazine. The closer you look the worse it appears. At some point you'll be looking at little wood fibers and thinking, MAN, I never realized that Beyonce's cheek was made of wood. Anyway, there is two ways to improve full screen presentation. One way is to use a higher capture resolution – 640x480 rather than 320x240 for example. Another way which is less intuitive is to use a lower screen resolution.

When I move my head from side to side the picture blurs and sometimes picilates. Does this have anything to do with my camera?

Blurring is usually due to a low-light level. Get a brighter light source, or open your drapes. Pixilation on the other hand, is usually due to a trade-off in the compression algorithm. Some video compression algorithms use lower resolution compression for an image which appears to moving a whole lot. This reduced compression results in pixilation.