Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: ApophisAstros on Apr 11, 2018, 22:30:12

Title: M31 Andromeda
Post by: ApophisAstros on Apr 11, 2018, 22:30:12
(https://cdn.astrobin.com/thumbs/L8QzVYgcEFn5_1824x0_g3HYCTwD.jpg) (https://www.astrobin.com/full/301991/E/)
Reprocessed this from last years data. (June)
120 x Lights 300s
20 x Flats
No Darks / No bias
Location Worthing
Canon 750d Modded
Using DSS 4.1 64 bit and Adobe Photoshop CC
Roger
Title: Re: M31 Andromeda
Post by: doug on Apr 12, 2018, 10:08:54
Nice image but I can`t put it on my report, Roger. When I enlarge it, it distorts the image too much. Can you put the image on here as a larger format .. then I can transfer it ..... hopefully.

Doug.
Title: Re: M31 Andromeda
Post by: ApophisAstros on Apr 12, 2018, 12:16:23
Doug ,
should be ok now.
Roger
Title: Re: M31 Andromeda
Post by: MarkS on Apr 12, 2018, 20:14:24
I've got to be honest, I preferred the single exposure version you posted in June on this thread:
http://forum.orpington-astronomy.org.uk/index.php?topic=11070.0

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10062/M31OAS.jpg)

The colours in both of them are quite a bit off so why do I prefer the previous one (above)?

1)  In the old one I can see faint structures reaching from M31 and almost meeting M110 whereas the contrast in the new version has destroyed that.
2) The overall colour of the new one is really brown.  I'm not sure why.  It seems to be a step in the wrong direction.
3) The core of M31 in the new one has interesting rings of pink and green.

In summary, the June version had a raw natural quality about it which allowed the colour cast to be "forgiven".  The new version looks overprocessed with significant destruction of the fainter structures.

Without knowing more about your workflow it's difficult to know what might have happened.  I wonder if something really nasty happened somewhere between DSS and Photoshop.

Mark
Title: Re: M31 Andromeda
Post by: ApophisAstros on Apr 12, 2018, 21:10:20
With regard to colour , everyone seems to colour their images differently to their own preferences ie

https://www.cloudynights.com/topic/614197-andromeda-galaxy-redux-with-new-64-bit-version-dss/#entry8512712 (https://www.cloudynights.com/topic/614197-andromeda-galaxy-redux-with-new-64-bit-version-dss/#entry8512712)

also on new DSS
, so because i liked the way it looked i went with it and there is loads of detail , even on M110 at the top.
Thanks otherwise Mark for the comments.
Roger
Title: Re: M31 Andromeda
Post by: doug on Apr 13, 2018, 09:51:29
     The new image looks very "stretched" across the space from left to right. I ain`t no imager; just how I see it.

     Doug.
Title: Re: M31 Andromeda
Post by: NoelC on Apr 13, 2018, 10:44:47
Love it Roger!
The intermediate detail does seem to have popped out a bit in your new one (well done).
Can't comment on the original (which seemed to be shifting a little), but as I'm partially colour blind I'm following the thread with interest in the hope of learning... 
Title: Re: M31 Andromeda
Post by: ApophisAstros on Apr 13, 2018, 10:56:45
I havent changed the width or clipped it , but first one was , also its 120 x the data than the previous one.
I have had good responses and likes from imagers on all other sites Astrobin,Cloudy Nights etc
Roger
Title: Re: M31 Andromeda
Post by: MarkS on Apr 13, 2018, 19:41:06
Quote from: Apophis
With regard to colour , everyone seems to colour their images differently to their own preferences

That's true and I certainly didn't intend to cause any offence. 

Mark
Title: Re: M31 Andromeda
Post by: JohnP on Apr 13, 2018, 19:49:36
Hi Roger - It's certainly a fine image but it does look a little over-processed. noise reduction is perhaps a 'tad' too much also can see banding down the RHS & top (I presume where you have stacked images from different sessions). Still I'd be happy with it - good job,  John
Title: Re: M31 Andromeda
Post by: Carole on Apr 14, 2018, 09:20:21
Taking a second look on a different screen, I think this reprocess is perhaps a bit "overcooked".  It is tempting to try to drag everything you can out of an image, I am guilty of this myself on occasions, but maybe a bit less noise reduction, and I think the background sky is too black. 

I can also see the stacking lines, but can understand why you wanted to keep that area in, you need to be a bit more subtle in disguising them in that case.

You have done extremely well in your first year of imaging, but do take heed of constructive criticism, they are not meant to offend but are a way of helping you improve. 

Carole
Title: Re: M31 Andromeda
Post by: ApophisAstros on Apr 14, 2018, 10:56:09
Quote from: MarkS on Apr 13, 2018, 19:41:06
Quote from: Apophis
With regard to colour , everyone seems to colour their images differently to their own preferences

That's true and I certainly didn't intend to cause any offence. 

Mark
No worries Mark, didn't take offence at all, always welcome yours and others  comments and suggestions , and a lot of the time i do take these ideas on board my processing.
Thanks again,
Roger
Title: Re: M31 Andromeda
Post by: The Thing on Apr 14, 2018, 13:12:04
Nice images but like me your processing is a bit hit and miss. i need to write a recipe for the gear and software I've got and stick to it.

Just a note, the average colour of the average galaxy is white. If you select the galaxy or most of it and look at the RGB figures with whatever graphics package you have the values shouldbe roughly even.

HTH

Duncan