Workflow and Image quality troubleshooting

[alinderbaum1]

Hello all -

I just realized I posted this in the wrong section of the forum, so my apologies for double posting! I am a new member to the board and very excited to join. I am a newbie to astronomy as well as photography/astrophotography. Prior to diving deep into the forum, I could use a little insight before proceeding any further.

While I have followed many tutorials on Startools processing, I have attached the one I used for this post, imaging M 42. I used this as a guide and followed every step and I also did just the mandatory steps (in addition to several other variations). I also have included a OneDrive link to the image results after each step in the process. This link should also contain the FITs file. I basically have 2 questions (that I am sure will open up many more).

First, after I WIPE, it seems that an underlying issue comes to light that I am not able to understand. I am sure it is light related as I am in a Bortle 7 (Houston TX) area. I did 30 second exposures at 800 ISO. Equipment used is listed below. Am I correct in that this is causing an obstacle to processing this image further?

My second question is , after I perform the WIPE module, every step after this provides the same result...which appears to be the same image I started with. I followed the steps prior to DENOISE as well.

Thanks in advance for any insight/guidance!


https://1drv.ms/u/s!At7UzxGKX97o7kvVGS6 ... P?e=WUa6qL


Aaron


Equipment used:

Celestron Omni 150 XLT Newtonian
Canon Eos 1000D
Advanced VX mount
DeepSkyStacker

[alinderbaum1]

I just noticed my link did not work. Sorry about that. Here it is again.

https://1drv.ms/u/s!At7UzxGKX97o7kvVGS6 ... P?e=yxb6yS

[happy-kat]

Hi
Wipe show a temporary auto dev so it is correct to need to autodev/dev again after doing the Wipe module.
Wipe works on the luminous so shows a B/W image (pick the colour button in wipe to see the colour version at that stage (1.6x startools)

[admin]

Hi,

Looking at your dataset, you are doing everything right in DSS now, which is great. The only issue (major one) is that your flat are apparently making things a lot worse. They are introducing an aritificial signal that is - in places - greater than that of the nebula itself! The single frame you uploaded does not show any of the patches, so this problem is definitely introduced by your flats.
How are you taking flats?

[alinderbaum1]

For flats, I was using the white tee shirt method, outside. 2 layers of a white tee shirt on the end of the scope held in place with a couple of rubber bands. I believe the histogram had the colors as close to center as I could get them. Is it better to have the histogram on one side or the other? Do you have any specific recommendations as to how to take these? I followed a couple of tutorials I found on youbute. I believe I took them at 1600 ISO, 1/4000 exposure.

[alinderbaum1]

Ivo,

Out of curiosity, I removed the flats that were bad and restacked. I followed the same workflow as above, undid tracking before Denoise and this was the result. I have not had the chance to redo the flats but did not think not having flats would result in the noise/graininess. Due to my inexperience I am sure I am overlooking something but wanted to put the link below in case something jumps out.

https://neuralanalytics-my.sharepoint.c ... w?e=LL68kj

[admin]

For flats, I was using the white tee shirt method, outside. 2 layers of a white tee shirt on the end of the scope held in place with a couple of rubber bands. I believe the histogram had the colors as close to center as I could get them. Is it better to have the histogram on one side or the other? Do you have any specific recommendations as to how to take these? I followed a couple of tutorials I found on youbute. I believe I took them at 1600 ISO, 1/4000 exposure.

That all sounds very reasonable. What light source did you use?

Ivo,

Out of curiosity, I removed the flats that were bad and restacked. I followed the same workflow as above, undid tracking before Denoise and this was the result. I have not had the chance to redo the flats but did not think not having flats would result in the noise/graininess. Due to my inexperience I am sure I am overlooking something but wanted to put the link below in case something jumps out.

https://neuralanalytics-my.sharepoint.c ... w?e=LL68kj

Any chance you can upload that to an area that is not restricted (e.g link to One Drive file for example)? Thank you!

[alinderbaum1]

Oops, sorry about that. Here is a better link. I also put one of the flats in there.

The only light source I could get to place the histogram close to the center was doing it outside, somewhat of a cloudy day. I tried a white screen Ipad and the histogram was all the way to the left. I am open to a better way!

https://1drv.ms/u/s!At7UzxGKX97o7kvVGS6 ... P?e=ldf5pY

[happy-kat]

There used to be an app for devices called LightBox, if it is still in the store it works very well.

[admin]

Your current flat frame looks like this;

Single__7871_ISO1600_Exp s__103F.jpg (246.18 KiB) Viewed 6404 times

It is somewhat atypical in that it doesn't show vignetting (e.g. darkening towards all four corners)as would be expected. It shows strange patches of light coming in and-out.
To give you an idea, this is a more typical flat frame (give or take the dust donuts/circles/specks);

lf_ir_g1o113_221_004620.jpg (117.94 KiB) Viewed 6404 times

It's not definitive proof your flats are bad, but definitely circumstantial evidence. Definitely try re-doing your flats. Try doing the tshirt method some time before dusk. Then go on to acquire your lights (obviously without changing the camera orientation!).