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First Proper Light with Skipper Billy's Old Scope! C&C please. Fairly Rough Processing

Jbro1985

By Jbro1985
in Imaging - Discussion

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Jbro1985

Jbro1985

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120 x 60sec Lum (1x1 bin), 60 x 60 Sec R, G & B (2x2 bin), 30 x 180 sec Ha (1x1 bin), 50 x Flats for each filter together with master darks and super bias.  6.5 hours total integration time.

Gear:  SWED80 DS Pro, 0.85 Reducer, SW AZEQ6 GT Pro, Moonlite CS Focuser / Stepper with HitecAstro Contro, ZWO OAG paired with ZWO185mc, ZWO EFWmini with Lum and ASI1600 tuned ZWO RGB filters together with Baader 7nm HA, ASI1600mm-c.

Pre-Processing:  Pixinsight

Post-processing:  Pixinsight, Photoshop (Carboni's tools and Topaz Labs)

Any comments or criticism always welcome. 

Special thanks to the Skipper!

 

Iris Nebula (ps).png

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cuivenion

cuivenion

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I'm not an expert, but it looks like the darks aren't matching very well. You've also used a lot of denoise. If you've dithered the subs maybe try stacking without using darks and see what result you get. If not it's possible to create a bad pixel map from your master dark. Nice image, love the Iris nebula!

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Jbro1985

Jbro1985

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Thanks Cuivenion.  I dithered every 10 frames. 

I think a big part of the problem is that I was having a quick go in the morning and my setup is in my (East facing) conservatory.  When it's a bright day I can't see a bloody thing on the monitor properly!  I can definitely see what you mean now the sun has moved to the other side of the building.  I'll be wary when I'm processing properly and I'll also take a look without the darks - they're not always necessary with the ASI1600mm-c and this may be one of those times.  Thanks buddy.

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jjosefsen

jjosefsen

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Not to be negative, but something must have gone wrong in stacking or as suggested in calibrating the subs.

I would have expected a much sharper result with that gear and integration time.

Do you have bad LP where you image?

Someone with experience with said camera might be able to chime in. But i have read that it

 can have problems with shifting bias signal at very short exposures, which might mess with calibration.

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kens

kens

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Correct - bias is not reliable with the ASI1600. Flats should be calibrated with flat darks instead.

Darks are needed for longer exposures due to the amp glow

Also, binning of subs adds little as it is done in software - may as well leave it to post processing, if at all.

I'm interested to know what gain was used and whether it was a dark site or light polluted.

 

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Jbro1985

Jbro1985

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Bad processing on my part I think. 

I'm going to have another go when I can see what I'm doing a little better!  Probably the weekend now.  

As above - it looked fine and smooth when uploaded (and when I was processing) but as soon as the brightness went from my conservatory and I could see more contrast on the monitor I could see it wasn't looking good!

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kens

kens

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You could be a bit overdone on Lum and a bit underdone on Ha - but you would need to look at unprocessed subs. How did you determine the exosure to use?

These days under LP I'm tending to forego Lum and just do RGB - or narrow band wherever possible

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Jbro1985

Jbro1985

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Just reviewed subs in blink in Pixinsight. 

Didn't bother the other morning... 

So I set SGP up to do 3 rounds of each colour etc. in cycle.  It seems the first two cycles (taken between 8pm and 12am) were much much brighter than the final cycle across all filters.  I need to work out why that was.  Anyway, two thirds of the data is garbage!  I'm going to see how we land if they're excluded. 

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jjosefsen

jjosefsen

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18 hours ago, Jbro1985 said:

Just reviewed subs in blink in Pixinsight. 

Didn't bother the other morning... 

So I set SGP up to do 3 rounds of each colour etc. in cycle.  It seems the first two cycles (taken between 8pm and 12am) were much much brighter than the final cycle across all filters.  I need to work out why that was.  Anyway, two thirds of the data is garbage!  I'm going to see how we land if they're excluded. 

Looking forward to seeing what you come up with.

It is quite a learning process I find. :)

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Jbro1985

Jbro1985

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Ok so I worked out the issue - by luck rather than skill.  It was actually nothing to do with the processing (though I've got a way to go).  

I exported as a PNG by mistake before I dragged and dropped into here.  The colours and resolution when bonkers for reasons u known to me.  I didn't save the PixInsight project from the Iris Nebula, but I processed some soul nebula data from Thursday (framing is off but I'm happy enough with it) - same thing happened when I exported only I could see it because it wasn't too bright in my conservatory.  I then re-exported as a tiff and it looked like the PixInsight version.  

Here's the Soul Nebula I caught on Thursday night.  Didn't get as much data as I'd have liked - meridian flip crashed Eqmod (one to fix another night) after I'd gone to bed.  I'm uploading from phone on commute so it's not the most detailed version but I think it shows the other problem was a non-problem with a dash of stupidity!

 

FB_IMG_1518976251904.jpg

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