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.

I am seeing this exact issue. Do you ever have a resolution?

Nothing changed for me. 1/31/22 images were perfect, and 2/3/22 are so under exposed. Same settings.

Thank you,

HI Matt,

same here…


Hi Markus, Matt … please why you do not refer directly to QHY support ?
You have really more chance to get a right answer.

Remember that your camera need the Direct Driver Beta Version (if you use the Direct Driver in Voyager), also try to install the latest SDK and camera driver if they have fixed the things.

All the best
Leonardo Orazi

Hello Leo,

unfortunately the attempt failed, there is not such excellent service in trouble-shooting as yours.
I was hoping that one of the two users here would have found a solution (with or without the help of QHY).

All the best,

Sorry to read about, I leave the thread open.

All the best

I’ve noticed the same. I put it down to high cloud but am interested in other ideas. Not loosing many frames but periodically have some frames that look like this.

Ok, I saw this topic now, sorry for the delay.

I solve the trouble after a lot of questions and investigation, finally QHY support give me and answer.

Is there a hole on the camera that needs to be cover by a small plastic tap.

without this cover some time a parasit light enters on the sensor.

In my case this works!!!

Thank Jose … to all … please considering also the european CCD/CMOS camera when you need for a new camera. Mechanical, electronics and drivers are at top level !

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