Digital & Video in Camera (I have a unique set of needs)

greenspun.com : LUSENET : Imaging Resource Discussion : One Thread

Ok. I started scanning a bit and I'll probably be reading more. I am the maintainer of not just the usual run of the mill web cam. After coming back from a small trip I am now finding that my current camera seems to be having problems (a Canon L1).

My problem at this point is that I'd like to find a digital camera that can also output a video signal Y/C would be preferred but will consider Composit. Here are the issues I have to deal with.

1) I need the highest subject DPI possible. What is subject DPI? Take a piece of paper or a ruler and bring your camera as close as possible to your subject w/o going out of focus. The physical size of the object in your image and the number of pixels you can capture (H/V) will then determine the subject H/V DPI.

Right now with my Canon L1 at approximately 18" away from subject with the 16x zoom lens I achieve a maximum subject DPI of about 400.

2) Since I also provide a Real G2 video feed from the camera using a second computer the replacement camera would also have to provide simultaneous output of continous video as well as providing snapshots through serial or USB interface..

3) It was my hope that I might achieve much better single images with improved subject dpi to retain the current video subject dpi.

4) Problems with lighting using macro mode. While I was excited about using macromode to get higher subject dpi my subjects are behind 1/4" glass. Their depth is roughly 1/4-3/8 of an inch hence when one brings a camera to within 1/2 of a inch of the glass (or 1.25" of the subjects) lighting becomes a serious problem (reflections from glass cause problems as well as shadowing from lights placed behind glass by the camera)..

As some last notes.. I am annoyed that imaging-resource doesn't have at least checkboxes for special features including whether the camera has video out. There are many cases in webcam operations where a person may want simultaneously high quality single images as well as video out to a second server which will produce the video feed. Using two cameras is not what I'd like.

Before I start talking to the manufacturers about my requirements etc. I'd like to know which digital cameras have video out (Y/C) preferred, macro mode, manual focus, exposure, shutter, etc.

Right now I don't care about how many images it can store - but since I want to get a second one as a standby it would be nice if I could get one that would serve a decent set of basic digital cam needs.. (mostly need to take pictures of equipment, or personal shots)..

I was most impressed by the Nikon Coolpix 950's macro mode but I don't think it has video out - also was concerned about lighting..

If anyone can at least list digital cameras with video out capabilities that would be helpful (I may just do this myself and put up a page while I wait). Other comments on how to improve what I'm doing now would be appreciated. One of the goals of using a digital camera was the hope that the single image dpi would be improved by at least a factor of two or possibly more than what I'm achieving currently with my Canon L1..

Sincerely, Randy Rencsok 517-371-3327 Webmaster AntCam - current home http://www.channelu.com/AntCam randy@channelu.com

-- Randy Rencsok (randy@channelu.com), February 28, 2000

Answers

How much do you want to spend? My uninformed guess is that you will be able to achieve good or at least usable continuous video from a video camera, as you do now, or good still images from a good still camera, but not both simultaneously from the same camera. Video cameras are capturing info optimized for rapid repetition of capture and playback, on a video screen. They have set limits, scan rates, etc, to allow transmission and playback on standardized devices. Still photography (digital or analog) can exceed those limits quite easily, but, in doing so, the information transfer issues slow repetition rates.

Have you considered two cameras working from different stands to the same point of view, then switching feeds/outputs or taking stills on a timed or as-commanded function? Using two much more optimized cameras could be easier than trying to make one device meet widely different requirements. You could potentially use a mirror or prism to divide between the two as well if only one output was ever needed at a given time.

-- Craig Gillette (cgillette@thegrid.net), February 28, 2000.


Moderation questions? read the FAQ