M31 QSI/ED80 and 350D

[Fay]

This is made up of 17x600, 0.85fr, L filter, QSI and ED80 in 2013 and 8x300 taken in France 2009, with WO ZS66 and 350D. really digging deep now!!!!!

[MarkS]

2009 and 2013 - you are certainly digging deep!

The luminance data looks great but the colour data doesn't really go deep enough and ends up being noisy.  It gives good colour to the stars though.

Mark

[Carole]

It has the makings of a good image Fay. 
I was advised to blur the colour from a DSLR as the detail is in the luminance or Ha and this can suppress the colour noise.

I'd be interested to see a result with this method.

Carole

[Fay]

I will have to have to have a go at it

[MarkS]

The way I dealt with the chrominance noise in my Cepheus Ghost was to add the RGB channels together to produce a far less noisy greyscale image.  Then merged the full colour version with the greyscale version using a luminance mask so the darker areas (where the noise was obvious) became less noisy greyscale and the brighter areas (where there is no noise) are full colour.

I reckon that is how this excellent image was processed:
http://www.jeffreyjongmans.nl/photo.php?id=55
Note that the really faint background dust is quite white i.e. devoid of any colour.

Mark

[Fay]

Mark can you explain a bit more on ow to do that please?

Also i was looking at the fantastic results from Luis Campos with his cooled mono 350D!!!

[MarkS]

Mark can you explain a bit more on ow to do that please?

In PhotoShop you would use a standard layering technique.  A good description is here:
http://www.astropix.com/HTML/J_DIGIT/LAYMASK.HTM

Sorry for the late reply - I've been on holiday!

[Fay]

glad you had a good holiday Mark
the colour info I used was not of high quality.

it was really an exercise to doing SOMETHING rather than sitting on the sidelines  due to permanent bad sky conditions.

all the same will have a go