QHY268M captured frames not equals

Dear all,

I am using last QHYCCD driver QHYCCD_Win_AllInOne.
On the same sequence I take these frames (with the same line definition, with gain 56 offset 25 600s)

what could be happen? a trouble with the driver?

Welcome Jose,

one image is taken in another side of meridian and target/stars is correctly inside … probably cause are veils /cloud/external light or fog in the sensor.

I dont see any reasons for thinking about a driver problem. In anycase if you think depends on drivers I suggest to open a ticket to the QHY support about … they are really responsive in this kind of questions.

All the best

Thank you Leonardo,

It’s not about the sky, I was looking when I take the pictures because this was the second night it happens.

It happens also with SGP, I checked later :slight_smile:

I follow you recommendation and I will post on QHY

Thank you again.

Hi Jose,

Are you using a filterwheel?

Make sure the filterwheel is done moving before the exposure starts. I had this problem and my exposures looked a lot like the ones you posted.


thank you Jacques, yes I am using filterwheel but the exposure is on Ha, in case of bad filter used seems to be more luminous?

I asked to QHYCCD about the “switch” HGC/LGC on readout Mode #1 (High Gain Mode) on this camera.
If you change gain 55 to 56 the behavior is completely different on captures. Maybe is a trouble with this setting on firmware. Maybe I need to move my setting from 56 to 58 to ensure the proper gain (currently I am using 56).
As they said on the website:

Readout Mode #1 (High Gain Mode). Please note there is a HGC/LGC switch point at gain55 to gain56. Gain0-55 uses LGC and Gain55-100 uses HGC.

Will see the answer from QHYCCD.

Thank you for your support.