Minimum Camera for Book Scanning

[Flowsen]

I was able to capture and download images with gphoto2 while the camera was running CHDK, so I'm pretty sure it's possible to get the combination working.

Are you sure? As already mentioned before, CHDK only acts in play or record mode of the cam. As soon as you connect using gphoto2 the camera turns to PTP mode. I agree, that your camera will still work with gphoto2 but you wont be able to take advantage of the CHDK functions. I tried it by placing a autorun script in CHDK that sets zoom and focus. As long as i turn on the camera in record mode, the script runs and sets zoom and focus settings. If i plug it into USB and running gphoto2, the script and the settings will be ignored.
By the way I am using a Powershot IS3, if you have success running gphoto2 and CHDK to interact with each other let me know.

As i have seen there are some "custom" CHDK builds with PTP support, this PTP supports enables the possiblity to send CHDK commands, scripts etc. Unfortunately, this only works for cams that do not already have PTP support included in their own firmware. Things are rarely documented so if I told something wrong or somebody has more information please let me know.

[pfarber]

I am in the precess of getting CHDK + PTP running on my SD780. With the PTP extension to CHDK you should be able to:

Snap a picture
Download it via USB via cmd line to process

From my readings on PTP you *might* be able to trigger the camera, download the image and even get a remote viewfinder image.

PTP is in *most* Canon camera since 2002, but feature support is different in each camera.

One thing the CHDK guy had learned is that when you plug in a USB cable, the firmware locks out certain buttons so you cannot use them (like trigger a pic, set the focus, etc). By adding the proper script to run via the cmd line you can unlock those buttons and take pics, download etc all over USB.

I was quite surprised to read all the features there were unlocking.

I did not find a SD780IS firmware, so it may be something the needs done... and the forum is still quite active talking about PTP development.

[pfarber]

It appears the SD780 work great under CHDK + PTP

"I will say this about PTP it is great for debugging. Thx for doing the initial implementation. I added it to the SD780 and love it."

Trying to e-mail the poster for specifics.. most of the dev thread is just snippets of debugging.

[Godisgr8t!]

Dan,

At the beginning of this thread you said this in a post:
"I still think the Powershot A590 IS is the best camera for the job in terms of price and performance."

My questions are: 1)Is this still the best camera for the job in your opinion? and 2)I didn't see the A590 in the list of cameras supporting SDM, do you know if it supports it?

Thanks!

[Rannoch]

Canon has 20% off of their refurbished stock.
The A480 is cheap and supports chdk. It is used by some folks on this forum.

http://slickdeals.net/forums/showthread ... &t=2486765

[reggilbert]

Dan,

At the beginning of this thread you said this in a post:
"I still think the Powershot A590 IS is the best camera for the job in terms of price and performance."

My questions are: . . . 2)I didn't see the A590 in the list of cameras supporting SDM, do you know if it supports it?

This may not be relevant if the A590 IS is different from the A590 in general, but otherwise . . .

According to this download list SDM supports the A590, in two flavors that seem to correspond to the two available versions of CHDK for A590 firmware listed here.

The lovely new glossary that is now a topic on the Hardware forum quickly provided me the SDM site link, by use of the "search this topic" function located at the top left of the topic page.

Reg Gilbert

[TomHorsley]

So, when the available supply of CHDK compatible cameras completely dries up, I wonder if more drastic measures could open up lots more cameras (literally). There are apparently DIY CCD camera hackers out there, see:

http://www.amazon.com/Ccd-Camera-Cookbo ... _rhf_p_t_1

and

http://www.amazon.com/CCD-Astronomy-Con ... pd_sim_b_1

I wonder if an arduino would be powerful enough to replace the brains of a camera? Just say to heck with the feeble capabilities the camera maker provides, rip the CPU out of the camera and drive the CCD with your own computer? (Not that I'm likely to attempt it anytime soon).

Another (much more expensive) alternative can be found in industrial control/machine imaging systems with things like these:

http://www.edmundoptics.com/onlinecatal ... uctID=2947

Or if you have $13,000 to blow, you could go for something like this:

http://www.alliedvisiontec.com/us/produ ... e4900.html

[daniel_reetz]

I am very interested in camera-building and have an "open source camera" in the form of the Nokia N900. However, there is another path - a very simple one - where we use a servo to press the shutter button, or where we use, say, the brake handle from a bicycle to press the shutters simultaneously. That will work with any camera ever, it's just a bit of mechanical work.

[TomHorsley]

That make me wonder if the external buttons all really just push microswitches, and if you could open up the camera and wire in some extra wires across the switches and "press the button" with a computer driven relay. I did something much like that (on a much less delicate scale) in my silly cell phone ring detector I used with my old phone:

http://home.comcast.net/~tomhorsley/har ... arkII.html

Heck, wire in enough of the switches and you could control every camera function with relays .

[daniel_reetz]

I've done that with the A530, it works just fine. See the images in this old thread where Xylon and I dissect our Canon Powershots and wire into them: http://www.diybookscanner.org/forum/vie ... 3&t=7#p386