Auto gain/exposure failing in Flats capture

[amitshesh]

I completed the sensor analysis on my QHY 533C camera. Then when I go to capture flats and try the auto gain/exposure button, it shows me an error message saying camera gain control is uncalibrated, and asks me to run Sensor analysis and try again. I have done so three times now, but to no avail!

What am I doing wrong?

Here is the screenshot showing the complete sensor analysis in the background, and the error message I get.

Screenshot 2025-03-22 at 11.37.04 AM.png (309.93 KiB) Viewed 3098 times

[admin]

Hi,

have you tried closing SharpCap and then re-opening and trying again once the analysis is done? I wonder if the calibration data is only checked for the point of view needed for the autoexposure when the camera is opened?

cheers,

Robin

[FEObs]

I too have this issue.
Seems the Brain or Sharpcap not finding the sensor anslysis data.
It is there in %APPDATA\ SharpCap folder.
It was working for me. Then today, redid calibration.
Went to brain but no luck. Closed down sharpcap and reopened to same result.

There are now several anslysis reports, all dated but can Sharpcap decide on one or do others need elimination.

In any event, my problem re-statwd for clarity is SharpCap not picking up new sensor analysis [or even older ones]

Anyone got any suggestions?

Thanks

[admin]

Hi,

do check that the camera settings you are using match those for which the sensor analysis was performed. The critical ones are 'Colour Space' and 'Read Mode' (some cameras do not have read mode, so you may not need to worry about that). So, for instance, if you analyse the camera in RAW8 and then try out the autoexposure in RAW16, the data is not compatible so cannot be used. You would need to perform the analysis in RAW16 to get the right data.

I would suggest avoiding any 'RGB' modes for this (and as a matter of general best practice too). You cannot perform sensor analysis in RGB modes since the image pixel values received by SharpCap are blended averages of neighbouring pixels rather than raw values from a single camera pixel. This may well mean that the sensor data measured in other modes will not be available to the autoexposure code in RGB mode, causing the sort of error seen above. Anyway, there are relatively few reasons to use RGB modes except for terrestrial imaging.

cheers,

Robin

[FEObs]

Hi Robin.
Thanks for that quick reply. But I have RAW16 and RAW8 done for both my Main camera and Guider. Both are QHY.
I am assuming changing offset or gain should not be an issue since the sensor analysis did exhaustive measurements at various combinations of those.
Jimmy
FEObs

[FEObs]

Hi again Robin
Just a thought
Can there be more than one sendor analysis per format?
Say, 2 or 3 different RAW16 analysis for same camera?

I re-read the manual and its my understanding a second sensor analysis relaces the earlier one.

Can SharpCap bain functions be confilused if there are several jdon files under each camera as opposed to one raw16 and one raw 8 for each camera?

If so, should I delete earlier ones?

Thank you

Jimmy

[admin]

Hi Jimmy,

no, doing multiple analyses shouldn't be a problem - the latest one is the one that will get used (the old ones will be overwritten by the new) - that sort of thing happens a lot when I am testing, so I am pretty confident it all works as it should.

Controls like gain, black level/offset and exposure should have no effect.

Can you please post the details of the exact filename for the sensor data file(s) that you have, along with a capturesettings file (snapshot an image using the camera - the capture settings file will be created alongside the image file and show all camera settings). Those will let me see if there is anything amiss in the settings/camera name/other things that might affect loading of the sensor data.

cheers,

Robin

[FEObs]

HI Robin
I did a clean new sensor analysis today.
Then saves the Capture profile with specific reference to "sensor analysis" and date.

Then I tried Capture/Capture Flats/Auto Adjust Gain/Exposure and error came into progress menu "sharpCap does not know the illumination, the camera is uncalibrated, redo sensor analysis.



Files appended below.

Thanks for your help

JImmy

[admin]

Hmm,

nothing odd there, so it is surprising that the analysis is not loading - I will need to try to investigate in similar situations and see if I can catch the bug. I will report back when I find something.

cheers,

Robin

[FEObs]

Thanks Robin.
Good luck.
Jimmy