Hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  Bode's nebulae  ·  M 81  ·  NGC 3031
Looking for contrast : M81 in fake Ha treatment !, 



    
        

            Ewam
Looking for contrast : M81 in fake Ha treatment !
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Looking for contrast : M81 in fake Ha treatment !

Acquisition details

Dates:
March 27, 2015
Frames:
40×96(1h 4′)
Integration:
1h 4′
Avg. Moon age:
7.55 days
Avg. Moon phase:
51.73%

Basic astrometry details

Astrometry.net job: 635148

RA center: 09h55m33s.4

DEC center: +69°0440

Orientation: -0.610 degrees

Field radius: 0.468 degrees

Resolution: 620x807

File size: 321.1 KB

Locations: La Gueule du Loup (Malonne), Namur, Namur, Belgium

Description

I was getting frustrated with the color balance on my latest M81 work : while playing with selective colors in Ps, the more I gained contrast and details the more the color balance seemed all wrong.

Then mister Coles's Ha version poped-up ! Eureka : "forget colors, I will start all over with broadband only subs and applied a "from B&W to Ha" action".

Here is the result : no pretty colors but definitely more to see!

> FINAL E : far from the "natural yet crunchy" aspect I was looking for, this last attempt (from the "fake Ha session) is all I could do. Too much processing leaves "naturalness" far behind I'm afraid ! Oh well, at least it's sort of blue (or is it blue green ? ;-)

> FINAL D : less saturation on the star field, more O-III layered in, little tweaking with artefacts... Next step will come out of Ha session and a dry night to get more detail (my sky is often very humid)

VERSION C : used 23 x 60 subs for background star color, added spikes, added 3 subs in O-III of 315 sec each @ 3200iso, using only 5% of relevant parts (faint extensions and softening the noise level)

Instead of O-III, UHC would have been more efficient, ... one learns slowly I suppose.

TECH SPEC :

23 x 60sec ;

12 x 90 sec ;

3 x 150 sec ; all set @ 1600iso ;

3 x 315 sec O-III @ 3200iso ;

Depth of field : dimmer than mag.18

The O-III here didn't seem to add more, maybe faint details on the outskirt - next version with extra O-III maybe ?

Comments

Revisions

  • Looking for contrast : M81 in fake Ha treatment !, 



    
        

            Ewam
    Original
  • Looking for contrast : M81 in fake Ha treatment !, 



    
        

            Ewam
    B
  • Looking for contrast : M81 in fake Ha treatment !, 



    
        

            Ewam
    C
  • Looking for contrast : M81 in fake Ha treatment !, 



    
        

            Ewam
    D
  • Looking for contrast : M81 in fake Ha treatment !, 



    
        

            Ewam
    E
  • Final
    Looking for contrast : M81 in fake Ha treatment !, 



    
        

            Ewam
    F

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Looking for contrast : M81 in fake Ha treatment !, 



    
        

            Ewam