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Any fix for amp glow ASI183MC

Posted: Tue Jun 19, 2018 10:08 pm
by johnc3457
Still dealing with the amp glow problem is there any work around, subtracting dark frames does clean it up some but still leaves some problemsImage

Re: Any fix for amp glow ASI183MC

Posted: Wed Jun 20, 2018 6:47 am
by Support@ZWO
Hi, there.
Are you use a uncooled version?

Re: Any fix for amp glow ASI183MC

Posted: Sun Jul 22, 2018 6:01 pm
by johnc3457
The camera is cooled and I still get the amp glow on the right side all read noise is usually taken care of by the cooling but amp glow is still present

Re: Any fix for amp glow ASI183MC

Posted: Sun Jul 22, 2018 7:38 pm
by johnc3457
ampglow frame 3.jpg
Attached file is cooled to -40 this reduced the normal noise but the amp glow at the right is very hard to remove even with dark frames. This was a 300 second exposure of M51 un stretched and with no preprocessing.

Re: Any fix for amp glow ASI183MC

Posted: Sun Jul 22, 2018 9:41 pm
by davebl
M8_120S_Sm2.jpg
I have the Mono version of this camera and I found that lowering the gain and using shorter exposures seem to help. I'm still experimenting, but my skies are filled with smoke right now, so I'm on hold. I'm attaching a 120 second exposure in H Alpha, single frame with dark subtracted. Cooling to -20c.
Dave

Re: Any fix for amp glow ASI183MC

Posted: Sun Jul 22, 2018 9:44 pm
by davebl
Here's the same image without the dark subtracted. It seems that the darks don't do a lot to hide the amp glow. My gain is set to 0.
Dave

Re: Any fix for amp glow ASI183MC

Posted: Tue Jul 24, 2018 6:07 am
by Support@ZWO
Hi
I think it is a inperfect calibration.
Dark frames maybe need to take again. with same exposure, gain, offset and temperature as light frames.
You can directly use master dark to calibrate light frame, without bias this time.

Re: Any fix for amp glow ASI183MC

Posted: Thu Jul 26, 2018 7:17 am
by Konihlav
for amp-glow tests (calibration tests) you may check my experience where I describe how to quickly check if calibration works (on CMOS cameras)
http://blog.astrofotky.cz/pavelpech/?p=1442
BTW with CMOSes there will always be a very, very little leftovers. Maybe only if you take the individual darks the same night (when camera was turned on) it might be 100% to calibrate out (so far I can reach some 99% which is OK for me).
Also, you have to use moderate gain, not completely zero and not too high.

Re: Any fix for amp glow ASI183MC

Posted: Thu Jul 26, 2018 1:03 pm
by Support@ZWO
Konihlav wrote:for amp-glow tests (calibration tests) you may check my experience where I describe how to quickly check if calibration works (on CMOS cameras)
http://blog.astrofotky.cz/pavelpech/?p=1442
BTW with CMOSes there will always be a very, very little leftovers. Maybe only if you take the individual darks the same night (when camera was turned on) it might be 100% to calibrate out (so far I can reach some 99% which is OK for me).
Also, you have to use moderate gain, not completely zero and not too high.
Thank you so much for share your experience, it's a good for all of our users.

Re: Any fix for amp glow ASI183MC

Posted: Tue Aug 07, 2018 5:02 pm
by johnc3457
Working on the calibration has helped a lot also limiting exposures to 120 seconds. Attached file is of M8 taken from high light pollution skies in downtown El Paso TX, I'm not sure what Bayer pattern is in use but with my old camera all of the Ha areas of the nebula were red, is the chip setup for RGGB or BGGR?