Pacman ngc 281 problems

[TiffsAndAstro]

got about 182 x 120sec subs last night. even though an ascom driver failed some point between me going so sleep at 1230 and my alarm at 4am. luckly, my last image was 3:49am so it could have been worse. (Basically, when my screen saver activates an ascom driver at random seems to crash. Solved before last session by deactivating my screen saver, but its been re-enabled by a forced update to non activated windows. so i activated windows just now    ) 

anyway...this is the best quick preview i can manage. it wasn't quick. i wasn't expecting a rainbow coloured image, but i was expecting more than this for 20k seconds (after culling a bit).

this image also causes problem in siril when re loading  it (screen goes completely white with some hint of dots). 

any comments etc very welcome. ill try processing the split out Ha and Oiii next but after seeing this im not hopeful.

Unless this is a not unrealistic result for my gear and skill? Which is quite possible  after veil, its not good

 

 

Edited 12 hours ago by TiffsAndAstro

[Elp]

I don't think there's anything wrong with it. To put things into perspective for you, I mostly image with my C6, six inches of aperture at F2. For this sort of thing I'd image for 10-12 hours minimum, in some cases I've gone up to 20-30 hours.

6 hours isn't really enough. Imaging longer you'll start to get the surrounding background signal too, it depends how "deep" you want your image to be, more time also means less noise so you can linear stretch much harder.

[TiffsAndAstro]

25 minutes ago, Elp said:

I don't think there's anything wrong with it. To put things into perspective for you, I mostly image with my C6, six inches of aperture at F2. For this sort of thing I'd image for 10-12 hours minimum, in some cases I've gone up to 20-30 hours.

6 hours isn't really enough. Imaging longer you'll start to get the surrounding background signal too, it depends how "deep" you want your image to be, more time also means less noise so you can linear stretch much harder.

Would you say this is a much less bright target than say veil nebula? I wouldn't have choosen it if that's the case

the stacked image looks ok, it's as if I lose contrast after a background extraction either via graxpert or sirils. Normally removing back improves contrast.

maybe I could cull more subs for cloud but it's hard to see in subs.

are using hyper star to get f2 on your C6?

Edited 11 hours ago by TiffsAndAstro

[TiffsAndAstro]

quick screen grabs of stacked image and then same image after gradient removal in graxpert. very odd

first image is after graxpert bge and below that is the original stack. 

 

 

 

Edited 11 hours ago by TiffsAndAstro

[Elp]

29 minutes ago, TiffsAndAstro said:

are using hyper star to get f2 on your C6?

Yes

[Elp]

Haven't used graxpert. Do you manually place your points? If not, try sirils DBE, and manually place points in a few areas, not on nebulosity or dark nebulosity, the sample points should be placed only on background "space", not on stars or anything else. Around 20 points will do across the image. Make sure it's cropped too so you don't have any stacking edges. Use the default RBF algorithm.

[TiffsAndAstro]

10 minutes ago, Elp said:

Haven't used graxpert. Do you manually place your points? If not, try sirils DBE, and manually place points in a few areas, not on nebulosity or dark nebulosity, the sample points should be placed only on background "space", not on stars or anything else. Around 20 points will do across the image. Make sure it's cropped too so you don't have any stacking edges. Use the default RBF algorithm.

Tried manual in siril too, got weird rgb coloured patches. Makes me think something wrong in the stack.

Gonna try flats from few days ago, see what happens. Ta for the help

[Elp]

I kind of get that when doing OSC. Think surrounding LP (especially lamppost light sources) is the cause. Not so bad when imaging more directly overhead.

Edited 10 hours ago by Elp

[TiffsAndAstro]

6 minutes ago, Elp said:

I kind of get that when doing OSC. Think surrounding LP (especially lamppost light sources) is the cause. Not so bad when imaging more directly overhead.

this is narrowband with my osc, and i've never seen it before....in all of my previous 3 goes at narrowband

im lucky for street lights, back garden is pretty shielded from them.

Edited 10 hours ago by TiffsAndAstro

[Elp]

3 minutes ago, TiffsAndAstro said:

this is narrowband with my osc

I know. All my optolongs do it. The 294 camera is the absolute worst for it, not too bad with other sensors. Doing lum RGB it doesn't happen so much, I think it's something to do with how the NB filters operate.

[TiffsAndAstro]

10 minutes ago, Elp said:

I know. All my optolongs do it. The 294 camera is the absolute worst for it, not too bad with other sensors. Doing lum RGB it doesn't happen so much, I think it's something to do with how the NB filters operate.

not noticed it before though with my svbony 220. tried different flats, remarkably similar result. Going to leave this one for now come back to it later after i attempt my mega-hodgepodge veil 4 panel update  

[TiffsAndAstro]

so i manually stacked 167/170 of my frames, and, while this will never be an apod  , im at least getting something like i was hoping for...so far.... more than red

 

[Stuart1971]

2 hours ago, TiffsAndAstro said:

quick screen grabs of stacked image and then same image after gradient removal in graxpert. very odd

first image is after graxpert bge and below that is the original stack. 

 

 

 

That’s really odd, what settings did you use in GraXpert..?

[TiffsAndAstro]

1 minute ago, Stuart1971 said:

That’s really odd, what settings did you use in GraXpert..?

my usual default ones that worked with everything else ive ever done. much as that is

graxpert is invaluable, but can be flakey at times

[TiffsAndAstro]

well im ok with this result. ok enough to put more time into it via channel splitting and or Ha/Oiii etc. anything to delay an update to my veil mosaic lol

yes its a bit blue