M31 keeps going green, lack of data or wrong processing ?

[Ewan]

Hi all, what with the terrible weather i have been 'brushing up' on my processing 'skills', i ran some old M31 data through DSS again but i always have the same problem, my image tinges green or blue, i cannot get any of the core yellow(ish) or any brown in the dust lanes. What am i doing wrong i keep going in circles ?

I appreciate the data was jpeg & over fills my frame (early days of imaging) but the data is good none the less.

Are my RGB/K levels too near centre & need to go more left then raise my Luminance levels instead ? (i have tried MORE rgb/k to the right then Lum to the left & vice versa which seems to do the same but i don't think it does)

Saturation is not too high i feel but im no expert, the cfore always blows out bright white & not small & yellow(ish) like i have seen on a lot of posts it's driving me mad

Any advice good or bad is much appreciated.

Happy New Year to all.

[Daniel-K]

thats down to the bayer matrix in DSS settings you need to select the right one for your camera

[Ewan]

Thanks Daniel, DSS does not have the matrix for my 600D so i selected the EOS 50D one, does anyone know the correct one for a 600D ?

[Ewan]

This may shed some light & i may feel like a donkey afterwards.

from what i have read its meant to be RGGB

[Daniel-K]

i normally just use the generic ones

[davew]

If you are stacking Jpegs then the Bayer matrix doesn't come into it.

If the version of DSS you're using supports the 600 then it will de Bayer automatically when using RAWS. You will probably never use FITS files from your camera.

If you have a processing program then do the colours in that. DSS is not meant for final processing. If you have to use DSS then alter the RGB levels to nudge the colours around.

Dave.

[Ewan]

Cheers dave ill try just that, just getting some very good (i hope) subs of M31 right now, iso 800 @ 200 mins, then some iso 1600 @ maybe 1.00 min then some @ 30 secs ? sound any good ?

[davew]

Sounds a great plan to me other than 200 minute subs may be over the top . You may find even 30 seconds will blow the Trap. Test as you go using ISO 800 and 1600. Take too many and play with them all tomorrow, the next cloudy day.

If you try lots of settings you'll find what suits best.

Re the Bayer settings. My camera doesn't appear there either. I unticked the FITS bit on mine many years ago. Make sure you have version 3.3.3 b47. I also used AHD rather than bilinear.

Dave.

[VigdisVZ]

If all else fails there is Hasta La Vista Green for Photoshop: http://blog.deepskycolors.com/archivo/2010/04/26/hasta-La-Vista-green.html

[Ewan]

Oh dear my bad 200 mins !!!!! lol I meant 2.00 mins , I'll look into the other advice as anything would help atm, just nice to get out for a bit

[ollypenrice]

This target can look a bit green before post processing. Hasta La Vista Green is a good idea. Make sure that the top left of the peak on each colour's histogram is in the same place and cut back the black point on whatever channel until they are.

Then try some gentle (gentle!!!) S curves in red and blue. In the blue ease the bottom of the curve up and the top down. Do the reverse in red.

Olly

[Ewan]

Thanks Olly, just returned to this post so sorry for the late reply, i'll give it a go on the data i have at the moment.

I tried piggy backing the 55-250 but to be honest i think my focusing was way out on that one & the lens is not fantastic i think either.

Thing is i have a stack shot through the C8 with the FR & i know it's outside of the frame size but want to get the processing right for when i get the correct subs next time.

I am also trying to persuade the wife to goto the South of France for a small break but i feel she knows why :-)