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Strange artefact in Luminance data

Processing Deep Sky NGC7023 NGC Objects
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Christian Bennich avatar
Christian Bennich avatar
Hey

Yesterday I started collecting photons on NGC7023 (Iris Nebula). I stacked last night's luminance data and played around with stretching and DBE etc., on the target. 

I have found a strange, more or less horizontal artifact or something in the data that I can't find in other images on Astrobin or elsewhere. 

Anyone that can help me understand what it might be?
I can see it very very faint in my data from my ASI2600MM.

I have added an example of the stacked output (strange artifact.xisf and an example of the light data collected last night here: https://drive.google.com/drive/folders/1BAH1IVtAdkbntvMt_U7B7Y9eephBeNP-?usp=sharing

Any input and/or thoughts??
Engaging
Christian Bennich avatar
Christian Bennich avatar
andrea tasselli avatar
andrea tasselli avatar
Ghost reflection from a bright star. Happens.
Christian Bennich avatar
Christian Bennich avatar
andrea tasselli:
Ghost reflection from a bright star.

That was one of my suspicions - never seen it before. 

Anything that can be done about it?
Change the camera angle or??
andrea tasselli avatar
andrea tasselli avatar
It can be avoided by shifting the sensor relative to the field. How much, however, it is hard to say.
Christian Bennich avatar
Christian Bennich avatar
These types of reflections, are they a result of camera/scope combinations or is the light actually reflecting in the dust?
Yin_Zhen avatar
Yin_Zhen avatar
Hi
Could you tell us more about your scope ? It is a newton, probably…
Addos avatar
Addos avatar
Dither your frames. Extended artefacts from secondary mirror supports should be mostly dealt with.
Yin_Zhen avatar
Yin_Zhen avatar
Dither your frames. Extended artefacts from secondary mirror supports should be mostly dealt with.

Good idea.
However, I had the same artifacts on my N SW 150/750 with dithering.
Yin_Zhen avatar
Yin_Zhen avatar
Christian Bennich:
I have found a strange, more or less horizontal artifact or something in the data that I can't find in other images on Astrobin or elsewhere.


As i said, i had the same artifact with my newton.

I covered the shiny screws attaching the spider to the tube and closed the back of the tube with a homemade cover.

Before :
https://www.webastro.net/forums/topic/241615-reflet/
After :
https://www.astrobin.com/uewtlk/
Christian Bennich avatar
Christian Bennich avatar
Christian Bennich:
I have found a strange, more or less horizontal artifact or something in the data that I can't find in other images on Astrobin or elsewhere.


As i said, i had the same artifact with my newton.

I covered the shiny screws attaching the spider to the tube and closed the back of the tube with a homemade cover.

Before :
https://www.webastro.net/forums/topic/241615-reflet/
After :
https://www.astrobin.com/uewtlk/

@Yin_Zhen - Great idea - I normally only cover the back when I do flats/darks in the morning. Will give it a "Go"

@Addos - I will indeed dither my frames as well. I did that previously with my DSLR - but after I got my ASI2600 I have not done so. But will definitely start again  😜