I managed to find the topic I was talking about and here's the link:
http://www.stopmotionanimation.com/dc/dcboard.php?az=show_topic&forum=10&topic_id=2549&mesg_id=2549&listing_type=search
Thanks for the link; that was an interesting diversion. Ironic the $200 P&S runs on while the $2000 dSLR craps out.
Just from a casual cruising of the Camera & Lighting subforum, you can see the uphill battle fought by the would-be stopmotion animator... cheap webcam, frustration
--> nicer webcam, progress
--> still camera
--> computer controlled still camera
--> multi-thousand dollar dSLR and macro lenses and computer-controlled camera gimbals and robotic arms
--> still wants MORE...
On that note, your A620 is what, 4-5 years old? What'd it cost, $300? So what if it breaks? It's way out of warranty. Will you repair it, or get a more modern, cheaper unit with more features and higher resolution? Something to think about.
On point, CHDK *may* be able to help you. If you can get the LCD to look exactly the way you want using the buttons, CHDK can probably (at least) automate the button presses for you. It can certainly disable auto-off for you. CHDK cannot however get to the video before the Canon firmware. While it's somewhat easy to overlay
more info on the LCD, AFAIK it's currently not possible to take it away.
(attached: CHDK sample drawing palette, but the low battery signal popped over.)Considering Canon went with a 115k LCD panel on the 620 I'm guessing the video output is 640x480ntsc/576 pal, coming in via a 720x480/576 Dazzle, so even if you can get the video out to behave, is it of acceptable quality? Compared to gorgeous 3072x2304 stills, with zero problems with any override you can come up with ending up on the final image. CHDK could definitely help you in various ways if you go this route, especially automating DoF series - but you have to press the shutter. This doesn't take into account your toolchain; if you're set on video, then you need video. But no video is going to look like high resolution stills.
Whatever you decide, sounds like you're itching to get a project going... have fun!