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

On Mon, Feb 06, 2017 at 08:06:18PM +0100, Oliver Bendig wrote:
> 
> > Marcus Meissner <[email protected]> hat am 6. Februar 2017 um 08:36
> > geschrieben:
> >
> > > 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"
>  
> You're absolutely right. That fixed the issue. I saw the plus but thought it was
> intentional. It was obviously generated by my mail client.
> 
> > 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.)
>  
> >From my tests only the first wait seems the has an impact. I reduced both waits
> after Press 1 and 2 to 0 and iterated ten times without problem.
>  
> for i in `seq 9`; do rm capt0000.jpg; gphoto2 --wait-event=270ms --set-config
> eosremoterelease="Press 1" --wait-event=0ms --set-config eosremoterelease="Press
> 2" --wait-event=0ms --set-config eosremoterelease="Release 2" --set-config
> eosremoterelease="Release 1" --wait-event-and-download=2s; 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.
>  
> The problem that always the same photo is written to disk still occurs. It
> occurs even if I execute two single capture statements manually. I have to wait
> some seconds between both calls and then the correct images were written to
> disk.

Took some time to find some time to look into it.

For the initial startup issue .... I spotted a small pattern which we could
use for waiting. The 0xd11b property (Available images) is send twice
with a value, but we can only start after it is send for the second time.

Have to think how to implement this correctly.

The second problem where it always return the same image. This is new.
Can you capture debuginfo for two consecutive captures that show this problem?

Ciao, Marcus

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