This post was last modified: 2023-01-27, 23:10 by npaisnel.

I used qDSLR successfully a few years back with this camera..but today cannot get get any exposure change.

This evening was a sunset TL, Auto Holy Grail

The laptop and qDSLR happily changes the exposure manually. I can control the camera, the in built qDSLR intervolavometer works and I can adjust ISO , shutter speed and aperture manually .

I have selected a reference area and have followed the instructions on pages 25-28 on the instructions.

Reference capture taken, taken set to manual, Auto ISO is off

Yet the full sequence of about 300 images, the exposure did not change at all, from plus 2 EV down to -4 EV
Exposure just stayed at 1/80 sec and f 4.5 ISO 100

I am guessing that i am missing some basic setting ..but cannot fathom what it might tbe.

I just remember using qDSLR a few years ago and it 'just worked'

This time, no auto control of the camera exposure with Auto Holy Grail, sunset and auto NTC

As I say, i can manually control the exposure via the laptop, but the Auto HG system does not change it at all.

Using the Linux / Unix app image as downloaded a day or two ago.




I am assuming I am missing some basic setting..but just cannot find it

Thank you

Since manual adjustments work, it doesn't seem to be a technical issue, maybe just a misunderstanding how the lum values an reference value work.
I'd recommend watching my tutorial about the holy grail shooting with qdslrdashboard where I show and explain the process once again.
https://lrtimelapse.com/tutorial/advanced/

Hmm thanks

The only thing I can see is that I did not manually set the manual exposure carefully enough at the start. and I had Large JPEG instead of the smallest..

but with 1/100 second exposures and 10 second interval this should have not been an issue.

I am using qDSLR via USB on a laptop running Peppermint Linux with the app -image.. v3.6.7

Camera set exactly as per instructions..Manual , Manual ISO , manual focus..

It is a grey morning here in Jersey and sunrise missed but it is getting lighter..so i have camera running again, pointing out to sea with a grey cloudy sky from my living room window. it is getting brighter as the clouds clear so i am hoping to see an exposure change

Maybe as you say I was not taking care of how close the reference and Luminance was ..I will play with it manually as it shoots and see if I can force exposure change.

Thank you

You can troubleshoot by observing the values, reference and lum. You can also do some test just inside by closing / opening the window blinds. Make sure to confirm the settings for Max / Min ISO/Exp before starting (sometimes this is necessary). Also check that you have Sunset/Sunrise set correctly.
Also note that qDDB only adjusts every 3 shots by default (you can change this in the settings).

This post was last modified: 2023-02-27, 12:46 by npaisnel.

Hi

thanks

Yes sunset was set...and the Max min settings were all set as default..and set to good values.

I had wondered about the settings change after the number of shots..I had set it to two on purpose to see changes quickly ..as this was merely being done for 'testing' to understand the app better.

I had Average pool size set to Off..and had wondered about that ..

It seems to be working in testing now...so yes, as suspected in my first post I think it was user error in the Reference /Luminance understanding.

Hey Gunter..thanks ..yes it as a Luminence Reference issue. I do not know what I did exactly ..but I guess I did not set the Reference value correctly first.

Thanks