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Unusable image quality when triggering with qDslr

Posted: 23 May 2017, 18:09
by Nestea
The other day I was shooting a day to night time lapse. Usually I shoot with a manual lens but this time I used my Sigma 24-105mm f4 with optical image stabilization (OS).
All of my images with longer exposure times turned out to be unusable.

After a few test shots I found out that the image quality when using optical stabilization is much worse when triggering with qDSRL.

All pictures I attached where shot with my Canon 5D Mark IV with the Sigma 24-105mm f4 Art on a stable tripod. I did not use mirror lockup or live live for this test.
- The one on the left was shot with optical stabilization turned OFF and triggered with qDslr.
- The picture in the middle was shot with optical stabilization turned ON and triggered with qDslr.
- The picture on the right was shot with optical stabilization turned ON and triggered with the 2sek timer in the camera.

It seems that the OS is malfunctioning when the camera is triggered with qDslr. Using OS on a tripod usually results in a worse image quality but they are still usable.

Has anyone encountered a similar behavior? Or is this a problem with my camera/lens combination?

Image Comparison.JPG
Image Comparison.JPG (172.6 KiB) Viewed 8981 times

Re: Unusable image quality when triggering with qDslr

Posted: 24 May 2017, 07:39
by GonzoG
It's not qDD issue, it's an operator error.
The attached photos (2 and 3) do not have a bad quality but are blurred by camera movement.
OS is for handheld photos, not for taking photos while camera is on tripod.

Re: Unusable image quality when triggering with qDslr

Posted: 24 May 2017, 09:14
by Nestea
I know that you should turn off OS when shooting on a tripod.
I was just surprised how much more shake there is (middle picture) when I trigger the camera with qDD.

When using the camera internal interval timer instead of qDD the pictures would still good enough even with OS turned on.

It cannot be an issue with the camera shaking otherwise the picture without OS would be blurred to.
So there seems to be a difference in how the OS reacts depending how the camera is triggered.

Re: Unusable image quality when triggering with qDslr

Posted: 25 May 2017, 07:33
by hubaiz
qDslrDashboard only sends the 'capture' command to the camera and the camera executes it, so not sure how could it has anything to do with lens OS as it does not have access to it at all.

Re: Unusable image quality when triggering with qDslr

Posted: 25 May 2017, 12:03
by cathy
Need a better tripod !

Re: Unusable image quality when triggering with qDslr

Posted: 26 May 2017, 16:47
by Nestea
The Tripod is not the problem. The images are perfectly sharp without OS turned on.

I did a bit more testing and I was not able to replicate the issue with my other lenses (e.g. Canon 100mm macro).
While the image quality (shake) is always worse with OS turned on while shooting from a tripod, with none of my lenses it is as bad as with the Sigma 24-105 f4.

Here is an example video how it looks like (1:1 crop). Starting at around 16 seconds you can see that the issue gets worse with longer exposure times.

https://youtu.be/BhVdSMh4As4

Re: Unusable image quality when triggering with qDslr

Posted: 27 May 2017, 05:37
by GonzoG
It's simple - read lens manual. It is clearly stated there that OS is not to be used on tripod.