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Is it amp glow?


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Hi all

I have been imaging with my self converted Canon 60d and some of my subs are spoiled by a pink glow in the bottom right corner of the frame.

I have experienced amp glow before with a 350d but it was persistent and in every frame above 4 min, these however come and go during an imaging session.

The glow isn't visible on the equivalent dark fames, which I find confusing.

I have added a couple of frames, one with the glow (bottom) and one without (top)

any suggestions?

Cheers

Bryan

 

 

IMG_6824.jpg

IMG_6826.jpg

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I think it is genuine nebulosity that you were capturing there.

Here is reference image with same area (and feature) marked:

image.png.980552ffd63121c04ce9916a7d99f88c.png

Fact that you can see that in some subs and not in others - just means variable sub to sub transparency (passing thin high alt clouds or similar).

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1 hour ago, Davey-T said:

Have you tried using an external power supply with dummy battery and if you're using a laptop capturing with the memory card removed ?

Dave

Hi Dave

Thanks for the suggestions, I am using an external power supply with dummy battery and saving images direct to the SD card on board.

I could maybe try capturing direct to the laptop and see if that makes a difference 

Cheers

Bryan

 

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2 hours ago, vlaiv said:

I think it is genuine nebulosity that you were capturing there.

Here is reference image with same area (and feature) marked:

image.png.980552ffd63121c04ce9916a7d99f88c.png

Fact that you can see that in some subs and not in others - just means variable sub to sub transparency (passing thin high alt clouds or similar).

Hi Vlaiv

I would love it if you were right but it appears on other frames of other objects in the same place

ill include an overstretched example of Caldwell 23

Cheers

Bryan

IMG_0893.jpg

P.s. Nice Image Vlaiv

Edited by assouptro
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2 hours ago, assouptro said:

Hi Vlaiv

I would love it if you were right but it appears on other frames of other objects in the same place

ill include an overstretched example of Caldwell 23

Cheers

Bryan

IMG_0893.jpg

P.s. Nice Image Vlaiv

I found it online - took a while to find one wide enough to display needed region.

Well, if it never shows in darks, have you tried flats?

It is highly unlikely to be amp glow that does not show in darks. On the other hand, light leak (though very odd looking) or "over sensitivity" in that particular region should show in flat files.

You don't need matching flats to diagnose that it is due to light - you can just shoot a set of flats and examine those to see if there is that sort of brightening in that particular region (probably under stretch).

If it is due to light, than it can be easily corrected by taking flats along your darks for your targets.

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2 hours ago, LightBucket said:

Looks more like light pollution to me, do,you use an LP filter ...?

Hi

Yes I use an Idas Lp2 filter, and it has been rotated to different positions and the "noise" appears completely at random during an imaging session but always in the same place on the subs

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1 hour ago, vlaiv said:

I found it online - took a while to find one wide enough to display needed region.

Well, if it never shows in darks, have you tried flats?

It is highly unlikely to be amp glow that does not show in darks. On the other hand, light leak (though very odd looking) or "over sensitivity" in that particular region should show in flat files.

You don't need matching flats to diagnose that it is due to light - you can just shoot a set of flats and examine those to see if there is that sort of brightening in that particular region (probably under stretch).

If it is due to light, than it can be easily corrected by taking flats along your darks for your targets.

Hi again

Thanks for your efforts!

It never shows up in flats and isn't corrected by adding flats to the mix. It affects about 3 in 10 frames building in intensity then disappearing until it starts to build again.

Here are another 2 shots taken on the same night (5 min subs)

Cheers

Bryan

IMG_1058.jpg

IMG_1059.jpg

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  • 1 month later...

Just a follow up in case anyone else has an issue like this and comes across this thread.

I have resolved the issue. 

It is the same problem I have with my modified 6d, which is as a result of shooting images directly after viewing the camera in live view. 

To resolve it, I unplug the power supply momentarily after I am happy with the focus and composition then start imaging from a blank screen. This has stopped the “glow” 

it’s obviously a flaw in the cameras, maybe introduced by me converting them or maybe it was there from start?? 

Anyway. Problem solved!

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