Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Camera Triggering

Everything camera related. Includes triggers, batteries, power supplies, flatbeds and sheet-feeding scanners, too.
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Camera Triggering

Post by curious » 13 Mar 2011, 22:12

This thread can serve as an index of methods for triggering a camera to take a photo. If you know of a method not listed here, please add it along with any links to more details about it. Also chime in if a method is mis-explained in this list.

This list is sorted by software, since software/camera compatibility limits choices: SDM, CHDK, gPhoto2, non-software (pneumatic, mechanical, electrical, etc.).

Using SDM (Stereo Data Maker, select Canon cameras only): Using CHDK (Canon something something, select Canon cameras only)
Using gPhoto2 (most cameras with PTP protocol, some others, see full list)
Pneumatic Using mechanical pressure and/or electrical pulses
  • Stock remote: some cameras come with remotes, and some of those remote/camera arrangements can trigger two cameras at once.

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Re: Camera Triggering

Post by dtic » 14 Mar 2011, 12:11

Two DIY designs for mechanical pressure triggers (using a small servo) on display here:
http://www.diybookscanner.org/forum/vie ... ?f=1&t=786

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Re: Camera Triggering

Post by TomHorsley » 15 Mar 2011, 17:23

Here's another possibility (that still needs SDM or CHDK): This test script can detect changes in light level by querying the Bv property (whatever that is):

Code: Select all

@title Bv test
 press "shoot_half"
 sleep 500
 get_prop 34 a
 print "Bv is", a
 release "shoot_half"
 sleep 500
 goto "loop"
So, if you have your lights on a switch, you could have an SDM script running that just goes ahead and takes the photo when it sees the lights come up.

Got this from a question I asked over on the CHDK forum:


This might make it simpler to just use the USB cable for nothing but file transfer rather than as a remote control.

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Joined: 12 Jul 2010, 21:06

Re: Camera Triggering

Post by E^3 » 17 Mar 2011, 01:05

Hello Bro,

Good Day.

Here is my simple Techno Blog Tutorials
http://cobecoballes-robotics.blogspot.c ... ation.html

The Video is included also
For Mono Camera Triggering

For Stereo Camera Triggering



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Joined: 12 Jul 2010, 21:06

Re: Camera Triggering

Post by E^3 » 18 Mar 2011, 04:23

Hello Brethren,


The blog itself had the videos.
Note: errata : Video URL are not found in Youtube.

The last video that I added is the combination of stereo capture and zooming, and the
script was done in Gambas2



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Re: Camera Triggering

Post by spamsickle » 29 Mar 2011, 14:24

I've been using a timer script under CHDK, which looks more or less like this:

Code: Select all

rem Timer shutter control for DIY Bookscanners
rem tested on Canon Powershot S5 IS   

@title DIY Timer Shutter V1

@param s Seconds
@default s 6
@param a Sounds (0=No 1=Yes)
@default a 1

if s<2 then s=2

   if a<>0 then playsound 4
   sleep 1000
until i<1
if a<>0 then playsound 0
click "shoot_full"
   get_prop 206 p
until p<>1
sleep 1000
goto "wait_interval"

rem Get_prop 206 tests when DIGIC III camera is ready to shoot again
rem Use get_prop 205 instead for DIGIC II cameras
rem Don't activate AE lock, this loop is endless if AE lock is activated

The only real drawback is that it runs like clockwork. If I get the page turned and the platen lowered in 3 seconds, but my timer is set to 6 seconds (which is the setting I've settled on), I waste 3 seconds waiting for the cameras to fire. If a couple of pages stick together, and I have to fumble with them, I may get a shot like this:
sm.jpg (149.19 KiB) Viewed 33582 times
This doesn't really bother me -- I used to be depending on a hardware switch, which would occasionally fire one camera but not the other. That was a real pain -- I couldn't just shuffle the images together, because the left and right would no longer match up. With the timer script, I get TWO bad images, and they still sort together just fine. Scan Tailor makes it easy to identify and cull them in post-processing, so for me it's not a problem.

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Re: Camera Triggering

Post by clemd973 » 06 May 2011, 22:37

My 2 cents...haven't found anything better than the Van de Kamp switch, especially since I don't do/know coding like Spamsickle. You can check out his switches here. Frans Van de Kamp builds these switches to your specs (RE: cord length, switch style). I've incorporated the switch in my build which you can view here, about half way down on the first page of the thread. Haven't had any problems with it at all. I even opted for the version of the VDK switch that has a timer; however, I don't use it because sometimes I have to adjust the book position, etc., which takes more time than what's assigned to the timer, and then there's a big mess. Think Spamsickle has pretty good results with his script version too. Quite a few options out there. I'd be interested to see more of them posted here. Thanks.

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Re: Camera Triggering

Post by stevede » 23 May 2011, 10:55

I second that, Clemd. I'd like to add that the VDK timer option allows you to plug in a momentary contact foot switch instead of the timer.
Here's one that looks just like the one I found in the garage....
http://cgi.ebay.com/250V-10A-Power-23cm ... 3f0a18b2f8
aIMG_1693.JPG (16.53 KiB) Viewed 32608 times

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Re: Camera Triggering

Post by kylefoley2000 » 28 May 2011, 15:51


first post. I'm having a lot of trouble building a trigger. The information on this site regarding building a trigger are extremely vague. I have found this site
http://www.instructables.com/id/Remote- ... ras/#step1

But I don't know how to connect that to a USB.

Also at this SDM site things are rather vague at how to begin.


If there is a button to push that will trigger the cameras I don't see why a computer software program is necessary.

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Joined: 16 Aug 2010, 13:10

Re: Camera Triggering

Post by Shaknum » 31 May 2011, 08:27

Here's a fun one. My cameras can take a remote trigger that uses a switch and a 2.5mm stereo plug, which is pretty standard. So as I looked over into my basement corner I noticed something that just might make my life a lot easier-Michael Sweet's (the lead singer of Stryper) guitar amp. Yes, 80s hair bands can still be useful. This amp has a foot-switch with a 1/4" stereo plug, so I found the appropriate connectors to convert my 1/8" plug on the foot-switch down to the tiny 2.5mm plug on the camera. I also split the cable so that it goes to both cameras. As luck would have it, it works perfectly. Now my machine is fast as lightning, and I don't feel guilty listening to "To Hell with the Devil" while I'm working :mrgreen: . Also the pedal is pretty industrial strength, so I don't think it will break down any time soon.

By the way Michael Sweet was a really nice guy, not something you generally expect from a glam-rocker.

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