M31 - advice please

[Skipper Billy]

Attached are two efforts at M31 from stacked RAW files - only 38 mins before the clouds rolled in !!

I can seem to get very subtle or very obvious (see attached) but not much in between.

Any pointers???  (I am new to this game)

Cheers

[Skipper Billy]

The above are the subtle ones - this is the 'obvious' one

[Owmuchonomy]

Hmmm, lots of things to think about. I will comment on a couple of things. M31 has a relatively very bright nucleus. Processing can include combination of different exposures to avoid burning out the core but bringing out the spiral detail. I used two separate data sets; one for the spirals, one for the core and used PS masking techniques to combine them. Perhaps you could also let the forum know more about your data; number of lights, darks, flats etc. this may highlight issues in the processing. Also, your FL is probably a bit too much for this DSO.

I have only done one M31 as follows:

[ollypenrice]

Start with colour balance. This is nearly all blue. If you have Photoshop (or similar) look at the histogram in each channel and try to get the top left of the main peak aligned in each channel.

You can only align them by moving the bottom left blackpoint slider to the right for peaks which are offset to the right.

In Ps you cna use the eyedropper tool set to colour sampler to measure yur background sky. R, G and B should be about the same in each. Blue can, if yu like, be a bit higher.

These are rules of thumb, no more.

Olly

[Skipper Billy]

Thanks guys, this is the result of 37 x 1 min lights - no darks or bias (clouds rolled in !!) and taken with a Canon 1100D and an ED80 (unguided).

It was really a session to play with Astrtortilla but gave me some data to play with.

[Skipper Billy]

Just a quick update - I have made some prgress I think - this is from the same data - no darks, flats or bias frames and 7 x 5 min subs. I am really happy with this - roll on the long dark nights!!  Thanks for all the shared knowledge - it is much appreciated.