Webcam "shutter time" etc

[popper]

Hi all!

I would like to use (near) realtime image analysis in order to measure and predict the positions of objects in motion. So I have some newbie questions about suitable camera hardware. I suppose that only webcams can send data (near) realtime to a PC:

- What "shutter time" does a typical webcam have? Can it be controlled from a PC?

- How well can the timing of taking a still image with a webcam be controlled from a PC?

- In what data format do still images arrive to a PC and can the format be controlled? Can I choose to use RAW format or is the image compressed to JPEG before I can do anything about it?

- How many still images per second (or seconds per still image) does a webcam manage? I mean, the 30 fps video stream at 0.3 megapixel is someting else than the 1.3 megapixel still image capability of most webcams, right?

- Can you suggest some webcam and/or software for controlling them?


What I require is sharp images taken with precise timing, sent (near) realtime to a PC. This is completely different from the video conferencing situation for which webcams are primarily made. I'd be grateful for any help and advice on any of my questions!!!

 

[Steep]

If you want high quality shots I think a compact digital would make more sense (linked to a pc), the shutter lag can be measured manually I suppose by taking a shot of a stop watch?

I suppose a lot depends on your budget though, a dslr has little or no shutter lag campared to a compact and there are many pc control solutions for different makes but the price goes way up.

http://www.steves-digicams.com/digsoftware_cameractrl.html

 

[popper]

Thanks for your reply!

If you want high quality shots I think a compact digital would make more sense (linked to a pc)

But compact cameras can't be remotely controlled from a PC, can they? I mean, the only thing they do when hooked up with a PC on USB, is to batch over all photos from their memory card. And in that mode they cannot take new pictures.

I've started to go through the software in your link, in order to see if they go with any compact cameras, or at least a small and not too expensive dslr.

The dslr:s I know of are just a tad too expensive and vulnerable-looking. And most of all, they are too large! A simple cheap small compact camera would be perfect for my need. If only it was possible to hook it up to a PC live. Strangely, not a single manufacturer has come up with that idea...

the shutter lag can be measured manually I suppose by taking a shot of a stop watch?

Yes of course, but I was wondering if they vary between webcams. No manufacturer mentions anything about "shutter times" in their specifications. There's of course no hardware shutter, so the question is whether it is controlled by firmware on the webcam chip, or if software in the PC can influence it.

 

[Steep]

PSRemote by Breezesys works with quite a few compact models.

Shutter lag exists because the camera is having to make decisions, like exposure, focusing, image type etc which takes it a split second, that split second will vary depending on what the camera has to do for each shot. Given a specific and repeatable situation it should be measurable and constant.

 

[popper]

Thanks!

Wow! If this is as good as it looks, it is all I have dreamed of! This is quite unknown, because I have searched alot and have not found it. Your reference has saved me much headache, and will soon sell Canon another camera!