Image Integration results very noisy

[souls33k3r]

1 hour ago, david_taurus83 said:

I've attached the 3 stacks ive done in Ha. These are are just the stacks, fresh out of preprocessing and just an STF stretch applied, no noise reduction. The Flaming Star one is a stack of around 4 hours of 5 minute subs. I feel this is also too noisy. It was because of this i decided to try longer Ha subs. So i stretched out to 900s! The Rosette is only 7 x 900s, just under 2 hours but he Horsehead is 16 x 900s, 4 hours. My favourite one as it needed nothing apart from a stretch! All used the same pre processing settings.

OK now I'm impressed. But you're clearly not using the ASI1600 camera. How do I know? Because Alnitak isn't showing the patent zwo pattern ? mind if I ask what scope, camera were you using? And how are you focusing? Everything for me is on point. Also what exposure lengths did you use for the flaming star nebula? What are you on the Bortle scale? I really don't see much in any of your images. I mean it is there but I'd be happy to have that level of noise. Maybe some parts of my answer will be within the questions that I've just asked above

[david_taurus83]

Haha it is indeed the 1600MM but the one with memory buffer.

Regarding Alnitak, I assumed it was the kind of scope and flattener combination. All images are shot with the WO GT71 and Flat 6A II at F4.6. I have a 10mm spacer between camera and filter wheel. I have 36mm Baader filters so can afford to do it. Tried it to reduce halos with the Oiii filter. Didn't work! Both flaming star and horse use the Flat 6 and the rosette uses the Hotech SCA, hence the dodgy stars. Still working on spacing. FYI, with the Hotech a do get the ZWO kaleidoscope effect!

Focusing with a Deepsky Dad autofocuser using APT to control.

 

Flaming Tadpoles were all 5 minute subs with dithering. Conditions weren't great. Lots of high cloud but it was early February, and the first few clearish nights we had since November! I wasnt happy with the results so I tried longer subs for the horse and rosette. 15 minutes with dithering. I will continue to shoot narrowband now at this length despite what all the maths and figures say about this camera and short exposures. I'm more of a, take a pic, see how it looks, kinda guy.

 

Bortle 6 zone with 3 streetlights directly plaguing the back garden.

 

For pre processing I I use the workflow described in the book Inside Pixinsight. If you don't have it its almost identical to the workflow described in the Light Vortex Astronomy tutorial except I don't use the Local Normalization or Drizzle routines as they take too long. If I was you, I would try the manual approach to pre processing and incorporate cosmetic correction. I've never really got on with the Batch Pre processing script. If you want, I can email you the process icons I use. They should load up with all the settings I use. Youd only need to change directory paths etc. Could compare the kind of noise levels to what I get?

[souls33k3r]

On 19/04/2019 at 10:13, david_taurus83 said:

Haha it is indeed the 1600MM but the one with memory buffer.

Regarding Alnitak, I assumed it was the kind of scope and flattener combination. All images are shot with the WO GT71 and Flat 6A II at F4.6. I have a 10mm spacer between camera and filter wheel. I have 36mm Baader filters so can afford to do it. Tried it to reduce halos with the Oiii filter. Didn't work! Both flaming star and horse use the Flat 6 and the rosette uses the Hotech SCA, hence the dodgy stars. Still working on spacing. FYI, with the Hotech a do get the ZWO kaleidoscope effect!

Focusing with a Deepsky Dad autofocuser using APT to control.

 

Flaming Tadpoles were all 5 minute subs with dithering. Conditions weren't great. Lots of high cloud but it was early February, and the first few clearish nights we had since November! I wasnt happy with the results so I tried longer subs for the horse and rosette. 15 minutes with dithering. I will continue to shoot narrowband now at this length despite what all the maths and figures say about this camera and short exposures. I'm more of a, take a pic, see how it looks, kinda guy.

 

Bortle 6 zone with 3 streetlights directly plaguing the back garden.

 

For pre processing I I use the workflow described in the book Inside Pixinsight. If you don't have it its almost identical to the workflow described in the Light Vortex Astronomy tutorial except I don't use the Local Normalization or Drizzle routines as they take too long. If I was you, I would try the manual approach to pre processing and incorporate cosmetic correction. I've never really got on with the Batch Pre processing script. If you want, I can email you the process icons I use. They should load up with all the settings I use. Youd only need to change directory paths etc. Could compare the kind of noise levels to what I get?

Maybe i need to ditch the BPP script and see if the image gets any better to begin with.

Would appreciate if you could PM me the process icons and i'll save them and work through them. 

Cheers mate

[iansmith]

One thought occurred to me on using longer integration times. The longer the integration, the smoother the target will be, but you will also get more faint stuff in the background, which is bound to be noisy. To me (looking on my phone) the main targets look great, it’s just the background where you have some noise. I don’t think there is much you can do about this other than targeted noise reduction on the background. 

Cheers, Ian.