Re: Canon 1300D: can only capture one image; second capture fails

On Fri, Feb 03, 2017 at 07:54:08PM +0100, Oliver Bendig wrote:
> Hi Marcus, Hi Volker,
>  
> > Marcus Meissner <[email protected]> hat am 2. Februar 2017 um 08:34
> > geschrieben:
> > What I think might be missing here is a bit of waiting between
> > the full shutter press and full shutter release.
> >
> > If you are curious to try something... This basically executes the
> > shutter commands the capture function does, plus some additional
> > waiting bettween "Press 2" and "Release 2".
> >
> > export LANG=C
> > gphoto2 --wait-event=1s --set-config eosremoterelease="Press 1"
> > --wait-event=1s --set-config eosremoterelease="Press 2" --wait-event=100ms
> > --set-config eosremoterelease="Release 2" --set-config
> > eosremoterelease="Release 1" --wait-event-and-download=5s
>  
>  
> I played a little with the timings. The first wait-event has to be larger then
> 270ms to make the camera release the shutter.
> 
> working:
> -----------
> gphoto2 --wait-event=270ms --set-config eosremoterelease="Press 1"
> --wait-event=80ms --set-config eosremoterelease="Press 2" --wait-event=80ms
> --set-config eosremoterelease="Release 2" +--set-config
> eosremoterelease="Release 1" --wait-event-and-download=5s
> 
> not working:
> ----------------
> gphoto2 --wait-event=250ms --set-config eosremoterelease="Press 1"
> --wait-event=80ms --set-config eosremoterelease="Press 2" --wait-event=80ms
> --set-config eosremoterelease="Release 2" +--set-config
> eosremoterelease="Release 1" --wait-event-and-download=5s
> 
> The shutter releases with every call. But after saving the file, gphoto get's an
> error -1:
> UNKNOWN PTP Property d11b changed
> UNKNOWN Camera Status 1
> UNKNOWN PTP Property d11b changed
> Saving file as capt0000.jpg
> UNKNOWN Camera Status 0
> *** Error (-1: 'Unspecified error') ***

You have a typo in the commandline ... "+--set-config" should be "--set-config"

 
> The jpg file was successfully written to disk and the file contains the correct
> image.
> The debug trace is here: http://bit.ly/2l0Bima
> 
> To test the reliability, I called gphoto in a for loop with 10 iterations. This
> didn't work reliable with a wait of 270 like in "single step" when called
> without any sleep between the iteration. I had to increase to 500ms to get the
> camera release the shutter in every iteration. With a sleep of 1sec after each
> iteration, I could decrease the wait to 360ms:
> 
> successfully captured 10 images:
> for i in `echo 1 2 3 4 5 6 7 8 9 10`; do rm capt0000.jpg; gphoto2
> --wait-event=360ms --set-config eosremoterelease="Press 1" --wait-event=80ms
> --set-config eosremoterelease="Press 2" --wait-event=80ms --set-config
> eosremoterelease="Release 2" +--set-config eosremoterelease="Release 1"
> --wait-event-and-download=5s; sleep 1; done
> 
> In the for loop, the jpg always contains the first image that was taken in that
> sequence. I moved the camera in between so that the image should differ. But it
> was always the first image from that loop.

I am also wondering if you can decrease or increase the wait after after the "Press 2",
which is the time we hold down the virtual shutter button.

I see you reduced it from 100ms to 80ms already.

(The gphoto capture code currently does not have a wait there, which is probably
the core issue.)

Ciao, Marcus 

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