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How do I get rid of my amp glow? Darks and flats don't help much.

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#1 jetbuilder

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Posted 09 February 2019 - 11:25 AM

I have an uncooled ZWO ASI178MM and am having issues with amp glow that darks flats and bias won't completely remove. Looking for suggestions on how to get rid of it completely so I don't have to crop it out.

 

This is a single 10 minute subexposure with a gain of 100.

single sub.jpg

 

This is the same exposure with darks flats and bias added in DSS.

single sub + darks bias.jpg



#2 Jon Rista

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Posted 09 February 2019 - 11:35 AM

How exactly did you calibrate? With what software? What settings?



#3 jetbuilder

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Posted 09 February 2019 - 12:16 PM

Deep Sky Stacker. Average for lights darks, flats and bias.



#4 Jon Rista

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Posted 09 February 2019 - 12:51 PM

DSS by default scales the darks. That is why it is not calibrating properly. You need to find the Dark Optimization setting and disable it:

 

4BI99rg.jpg



#5 Gipht

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Posted 09 February 2019 - 12:58 PM

In DSS under the stacking settings, under the darks tab,  there is a check box that can be selected for Dark Multiplication factor.  You might try adjusting that factor to something like 1.5 to reduce  the  amp glow if  what Jon suggested  does not work.



#6 jetbuilder

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Posted 09 February 2019 - 03:27 PM

Dark optimization was already unchecked. I upped the dark multiplication and it just darkens the area right at the corner. It does nothing to the rays going across the frame.



#7 Lite2

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Posted 09 February 2019 - 05:47 PM

Dark optimization was already unchecked. I upped the dark multiplication and it just darkens the area right at the corner. It does nothing to the rays going across the frame.

I believe that is from a bright star just out of the frame.



#8 jetbuilder

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Posted 09 February 2019 - 07:03 PM

I believe that is from a bright star just out of the frame.

the amp glow is constant no matter what target I'm pointed at.



#9 Jon Rista

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Posted 09 February 2019 - 07:08 PM

Dark optimization was already unchecked. I upped the dark multiplication and it just darkens the area right at the corner. It does nothing to the rays going across the frame.

Disable dark multiplication as well. You need entirely unscaled darks, and dark multiplication is just a manual way of scaling the darks. Disable both, and see if that helps.



#10 Gipht

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Posted 09 February 2019 - 10:24 PM

If you could print a copy of your stretched master dark for the exposure time, temperature,  and gain used here, it might help us diagnose the problem.



#11 Jerry Lodriguss

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Posted 10 February 2019 - 03:19 AM

This is from a DSLR guy, so it's probably worth nothing, but if you are using BIAS frames, try checking ON "set black point to zero" under RAW/DDP settings tab.

 

I'll be curious if this works.

 

Oh, and if you Do use a DSLR, then do NOT check this on.

 

Jerry


Edited by Jerry Lodriguss, 10 February 2019 - 03:20 AM.



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