I have been playing around with a couple of GentWire USB2 Canon triggers, CHDK and two ELPH 110 HS cameras (one converted by MaxMax for NIR images). My goal was to get them to take a picture at the same time so that I can use the images for stereographic measurements. However, the timing of the cameras is all over the place. Sometimes one first then the other, sometimes one doesn't take a picture, sometimes the response is fast, sometimes slow, etc...
I have tried connecting both trigger wires to the same RC Out (9) as well as separate RC Outs (9 and 11), but the results are the same. I'm telling Mission Planner to "Trigger Camera Now" from the flight data screen while the machine is on the bench.
Does anyone know where the issue lies and is it possible to get them to take a picture at the same time? A voltmeter is the only tool I have at the moment. I'm guessing that the issue is in either the CHDK environment on the camera, or in the camera itself. I've tried using the KAP script to force the parameters of the camera to be the same so it's 'searching' for the right settings before taking the picture. I just want a dumb, take picture now response, from the camera.
I don't have two of another kind of camera to try different responses with, but I know my Sony a5100 with a Farsight Mono cable has a much more consistent trigger response. The gentwire cable doesn't work without CHDK installed, does someone know of an alternative to use? I have a couple of artificial finger triggers that I haven't tried, but I would be surprised if they have better performance (although I could be wrong).
Any help would be appreciated, thanks!
Replies
I would make sure that focus is fixed and that other settings are not set to automatic.Then I would point both cameras at the same clock that measures fractions of seconds in order to measure the delays between each camera. If the delay is consistent then delay codes can be made to individually trigger the cameras. I have a Go Pro 3D kit that comes with synchronizing cable/modules and it looks complex. I think synchronizing cameras can be a bit of a challenge.
The only suggestion I can give is to verify all your settings match exactly IE ISO, aperture etc. Second is that your SD cards also must be rated the same speed. Like Warren said you must have your camera in complete manual mode. Off the top of my head we were able to have the elph 300 cycle at 0.8 seconds when using the intervalometer in manual.
You probably want to check out SDM (StereoDataMaker). SDM was developed from CHDK specifically to overcome the problem you are having, I think. It was designed for people to make stereoscopic photos with sync rates of "a fraction of a millisecond". When I first started doing photogrammetry for archaeology, I also got a custom stereoscopic rig and messed around with 2 canon s100s running SDM. Was fun to play with, but ultimately not particularly useful if you were ALSO doing photogrammetry (of small things on the ground).
I haven't played with sdm in a few years, but I guess it is still being actively developed (and the stereo sync has become less of the focus).
Check out the main page here:
http://stereo.jpn.org/eng/sdm/index.htm
and the install assistant (like the handy one for CHDK) here:
http://www.zenoshrdlu.com/assist/assist.html
Looks like your 110hs is on the supported list, so you should be able to install it easily with the ASSIST program. Do that for both cameras, and then mess with the "synchronization" menu, I think.