CHDK as a high-end webcam

haunma

Hi experts,

I would like to set up a CHDK-enabled camera in intervalometer mode, but for my application I need to transfer each image to a PC after shooting. Think high-resolution webcam with long exposures and a frame rate of something like one to four frames per minute. I don't yet have one of the Canon cameras, but was thinking about an A620. Some questions:

1) Does the USB interface emulate a mass-storage device?
2) Can CHDK scripts be running, taking pictures, etc. while the USB interface is active and transfering files from the memory card?
3) If the answer to #2 is no, is it possible to kick the camera back and forth between picture-taking and downloading modes from a USB-connected PC, without pressing any buttons on the camera?

Thanks in advance for your suggestions,

Mark

Barney Fife

Deleted

haunma

Interesting... I did not realize there were such programs available. (My current camera is a lowly Fuji that takes great pictures but is depressingly unhackable.)

The application is a night sky patrol camera for aurorae, meteors, etc. It might be possible to get by with the standard firmware, but I would prefer to eliminate dark-frame subtraction, shoot RAW, and also potentially go to slower shutters than the standard limit. Hence CHDK...

I'd plan to drive this from Linux, too, so I will look into Linux-based remote capture SW.

Thanks,

Mark

haunma

So after some research, I found remote-capture support for Canon digicams in the open-source gphoto2 library and command-line app. (This is mostly for Linux, but you could build it on any platform.) This should make it easy to build scripts that do whatever you like.

However, I was not able to find any information on CHDK + gphoto2. Are there any Linux users here? Do you know if gphoto "plays nice" with CHDK? Have you tried remote capture? I'm not keen to buy a camera for the purpose of trying this out.

Thanks,

Mark

fudgey

I tried 'gphoto2 --capture-image' on my A570IS with no success (didn't try without CHDK, though):

*** Error ***              
Sorry, your camera does not support generic capture
ERROR: Could not capture.
*** Error (-6: 'Unsupported operation') ***

'gphoto2 --get-all-files' works fine for downloading the images from the camera via USB (yes, with CHDK), and I believe the CD shipped with the camera has some Windows and/or Mac software with some remote control abilities (never tried any of those, just read somewhere) so I suppose it wouldn't be impossible to get gphoto2 to work with this one as well.

The A620 seems to be listed on gphoto2 remote control list so it should be more successful.

martinF

Not all Canon PowerShot cameras support remote capture operation.
See the list
http://www.breezesys.com/PSRemote/features.htm

There is also a open-source tool for periodic image capturing

http://capture.sourceforge.net/

Dapjazz

My PowerShot A550 doesn't support remote PC control/capture, but it would be great if chdk can change it! I'm using it with chdk, works GREAT, but really need this option, and can't buy another cam :😀

kwf

Dapjazz
My PowerShot A550 doesn't support remote PC control/capture, but it would be great if chdk can change it! I'm using it with chdk, works GREAT, but really need this option, and can't buy another cam :😀

I would say that it may not be impossible, but it may help to have one camera with CHDK and working remote capture. Then one could try to analyze the difference of the firmware from two cameras, one with remote capture, one without. They should be as similar as possible. Then one could watch which tasks are running when remote capture is working. I would not be TOO surprised, if this task/function is also existing in cameras without remote capture, waiting to be started. Another problem is that the remote capture program may not want to talk to the unknown camera.

But I do not have a Canon camera with remote capture so i cannot try it. Maybe there are some tasks or functions with suspicious names? Haven't looked ...