M31 - 11.5hrs finally processed

[Guest]

 

Details
Object name	Andromeda Galaxy
Object ID	M31
Date(s)	28/10, 29/10, 1/11, 2/11, 11/11
Telescope	Teleskop Service 65mm quad
Camera	ASI1600MM
Luminance	191 x 1 min = 191
Red	58 x 2 min = 116 min
Green	59 x 2 min = 118 min
Blue	60 x 2 min = 120 min
Ha	29 x 5 min = 145 min
Oiii	0
Sii	0
Total time	11.5 hrs
Frames	0
Processing	PixInsight / Bias, Flats, Darks (No Flats on Ha) / MorphologicalTransformation / LocalHistogramTransformation / ATWT
Notes	This imaging stretch was unexpectedly long and by the end of it I was almost looking forward to some cloudy skies so I could start working on the 12 hours of data I’d managed to collect. (I’ll remember I said that 2 months from now from under the leaden winter skies of southern Britain).   Capturing the data was relatively straight forward. The observatory was started each night quite easily with no snags. I was imaging within about 15 minutes of start-up each night avoiding any elaborate alignment routines by using Stellarium Scope with a one-star alignment.   My real challenge with this data was the complexity of processing the 5 channels.   Each time (and there were 4 attempts) I got close to thinking I’d nailed it, I’d leave it for a day, return to it and see nothing but a monstrosity…and start again.   It’s taken a long time but I’m glad I persevered as I’ve learned a lot of processing skills that have solved persistent problems I’ve had in the past with multi-channel images.   One of the biggest solutions was discovering that over processing the individual channels before combination (Lha, RhaGB) would produce a very noisy result – and appear washed out. I forgive myself for this one as the only other LhaRHaGB image I’ve processed was the Orion Nebula where the challenges from a light perspective are quite different. I’ve also mastered DynamicBackgroundExtraction in Pixinsight – some of the unprocessed subs were amazingly badly illuminated and DBE solved that – now that I’m using it correctly.   Surprisingly I found, yet again, that there was no need to use flats on the Ha channel. In fact, using it cast a band of light down the right side of the image. This was obvious in the flat itself and I’m not sure what’s causing it. However, without the flat on Ha the picture was evenly illuminated. Processing attempt number 1 was chewed up confirming this.   One of the reasons I’m pleased with this rendition of M31 is that I’ve avoided overdoing the Luminance and Ha channels and so haven’t got a massive light plume around the galaxy. This has also persevered the detail within the Ha regions and the hotter, younger bluer stars on the outer edges of the galaxy.   There are defects in the background where I had frost dots on the Luminance that I couldn’t get rid of completely and had to use 5 stamps from the CloneStamp to get rid of them on the lower left and right at the bottom in the centre. That area was actually a series of 5 red dots of unknown origin.   I’m also less than pleased with the area between the red inner core and the blue outer reaches. It looks somewhat green although I’ve eliminated green with SCNR. I think perhaps my use of RangeSelection would’ve been better than a CloneMask in raising the saturation. I don’t have the guts to try processing this again right now ?   David Liaromatis Welford Observatory November 2018

[Stargazer33]

Lovely detail and you've controlled the stars extremely well. It's just a shame M31 is cut off on both sides.

[Guest]

1 minute ago, Stargazer33 said:

Lovely detail and you've controlled the stars extremely well. It's just a shame M31 is cut off on both sides.

Thanks Bryan - you're quite right about the composition - but, like the top of my bald head - it's sometimes useful not to plant the subject square in the middle of the portrait LOL!

Using the 65mm on this in portrait view I've always enjoyed the blue star at the top looking down on Andromeda - just can't get myself to give it up ?

Thanks

David

[Sunshine]

M31 has been trending recently, i wonder if intelligent life there knows they're in the spotlight, another beautiful Andromeda shot, congrats, its wonderful!

[Laurin Dave]

Great image and interesting write up.. 

Dave

[Guest]

7 hours ago, Sunshine said:

M31 has been trending recently, i wonder if intelligent life there knows they're in the spotlight, another beautiful Andromeda shot, congrats, its wonderful!

Such an intriguing thought ? !

And wouldn't it to be cool to see their pictures of our galaxy and to find out what they call the Milky Way?

Thanks

David

 

[Guest]

I just realised that I'd listed the telescope used for this image as my Altair 115mm - it wasn't (and I've edited the post now) it was the Teleskop Service 65mm quad.

Remembering now that I won the March 2013 Hot Shot Image of the Month in Sky at Night magazine with this object and scope - I wonder how they'd judge this one in comparison?

David

[Guest]

I processed this on a 32" Sony Bravia and have only now opened it on my LED back lit monitor - wow - looks pants LOL!

Much darker and richer on the TV (I had checked the TV settings to ensure they were in normal mode)

I think the LED monitor might be a bit bright though too - anyone out there with an LED back lit monitor to tell me what it looks like - i.e. can you see a mass of mess in the lower left where I had to get crafty with the clone stamp? LOL!

Oh well, can't be helped - the question is - which to process on in the future - think I might keep using the Sony or I could just turn down the brightness on the LED????

David

EDIT: Having just closed this down and re-opened it on the LED I think it actually looks a lot better on it ? ...the Bravia is quite a bit more contrasty and not as subtle....oh the dilemma! LOL!

[Allinthehead]

Very nice David. The Ha regions really pop. 

20 hours ago, David_L said:

anyone out there with an LED back lit monitor to tell me what it looks like - i.e. can you see a mass of mess in the lower left

I didn't notice until you pointed it out. ?