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Re: Cameras for the Hackerspace Scanner
Posted: 13 Jan 2014, 12:18
by mhhelle
I decided to go ahead with the A810. I bought two refurbished from Canon for $59.99 a piece (plus tax and shipping). They come with a year warranty. It looks like I could have bought a used on one off ebay cheaper but decided I didn't want to wait and didn't want to roll the dice on a used one. I decided that it would probably be better for me to have better chdk support and that the image stabilization was probably not worth the extra $20/camer. One thing I did notice is that the prices on Canon's website seem to fluctuate-- the first time I was looking at them they were closer to $45 a piece.
Re: Cameras for the Hackerspace Scanner
Posted: 13 Jan 2014, 13:47
by rkomar
Is the image stabilization all that important when the cameras are bolted into a rig? I usually have mine turned off to save on battery power.
Re: Cameras for the Hackerspace Scanner
Posted: 14 Jan 2014, 23:45
by daniel_reetz
rkomar wrote:Is the image stabilization all that important when the cameras are bolted into a rig? I usually have mine turned off to save on battery power.
As far as I know, it's not. Check your shutter speeds - if you're capturing faster than 1/30th/sec, I'd say you're fine.
Re: Cameras for the Hackerspace Scanner
Posted: 22 Jun 2014, 15:22
by jkn
Hi All
here in the UK I can get either of the following Canon Powershot 'A' cameras cheapish (ie refurbished by Canon):
A1400 and A2500
The main differences between these two models that I can see are:
A1400:
optical viewfinder (handy for non-bookscanner applications, perhaps)
a bit 'chunky'
A2500:
no optical viewfinder
a bit slimmer
Also, the A1400 appears to have a bit less of a 'chrome' finish, especially in the rings around the zoom. There is a bit more reflective surface on the A2500.
CHDK support seems similar for each. Any suggestions about the best model to buy?
Thanks a lot
jon N
Re: Cameras for the Hackerspace Scanner
Posted: 22 Jun 2014, 16:29
by daniel_reetz
A1400 is well supported by SpreadPi - I'm not sure on the status of the A2500. Chrome is easy to tape over or paint, so don't let that guide you too much.
Re: Cameras for the Hackerspace Scanner
Posted: 23 Jun 2014, 17:12
by jkn
Hi Daniel
daniel_reetz wrote:A1400 is well supported by SpreadPi - I'm not sure on the status of the A2500. Chrome is easy to tape over or paint, so don't let that guide you too much.
OK, thanks. I am hoping that I may be in a postition to assist with SpreadPi at some point; regardless, I think I'll stick with the A1400.
Cheers, Jon N
Re: Cameras for the Hackerspace Scanner
Posted: 01 May 2015, 06:31
by davidfkane
Hello, I have been away from this forum for a while. I made the DIY scanner and have used it with moderate success. My problem has been the cameras that I used. I used the Canon PowerShot A3200. It seemed like a bargain at the time, but the cameras had two serious limitations. Firstly, there was no way of setting the focus, either manually or through CHDK. Second, I would prefer the cameras to be triggered electronically, via a button. I find that the dual brake lever is not optimal.
What is the best camera to use currently - assuming that cost is not a big issue. I would also like it to work with the Raspberry (SpreadPi).
Thank you so much for your help.
David Kane.
Re: Cameras for the Hackerspace Scanner
Posted: 01 May 2015, 11:33
by duerig
I'm working on collating a new guide for control and camera stuff for use with kits. For now, here are the cameras that are known to work best with CHDK/SpreadPi:
Canon Powershot A1400
Canon Powershot A2500
Canon Powershot SX160-170
Canon Powershot A810
But it is possible that the Canon cameras you already have can now focus. Update to the latest version of CHDK and try a different permutations of focus lock options using the CHDK console. In the Spreads CHDK module (see
https://github.com/DIYBookScanner/sprea ... kcamera.py for the whole thing), the _set_focus() method looks like this right now:
Code: Select all
focus_distance = self.config['focus_distance'].get()
self._device.lua_execute(
"press('shoot_half');"
"sleep(1000);"
"click('left');"
"set_aflock(1);"
"release('shoot_half');", do_return=False)
time.sleep(0.25)
self._device.lua_execute("set_focus({0:.0f})"
.format(focus_distance))
Perhaps this sequence will work for you.
BTW, depending on your budget, the Nikon 1 J4 cameras look like the best prospect for the near future to get high DPI scans. You would use gphoto2 to control it, and it is mirrorless with no mechanical motion when you capture a picture. Right now, it seems like you can get them for a few hundred each, which is very cheap for a DSLR-grade camera. I want to get my hands on one and see how well it works.