Faint fuzzy Part III

kinetic (Steve) · #1 25-01-2009, 01:15 PM

Hi,

I managed to get NGC5128 this morning before my Comet Lulin
revisit.
(Comet thread here:http://www.iceinspace.com.au/forum/s...ad.php?t=40369

This time I added some R,G,B to it but I couldn't get the balance
or the mix right. As always , the Lum looks much better

I tried a ratio in the mix of: L+ R(15):G(22):B(33).
This seemed to give , at least to my eyes, a realistic looking
colour without affecting the Luminosity resolution too much.

Still very much a beginner at LRGB!

Steve

renormalised (Carl) · #2 25-01-2009, 02:09 PM

Steve, I had a b it of a play around with your colour shot. I know why you had so much trouble with the colour...your blue histogram was so tight, it was almost just one peak, no spread in the blue values at all and your green predominated. So I played around with the output values, tried to fix the colours as they were clipped (esp' the blue) and ran an unsharped mask over the piccie (I also dodged the mask to clean up the edges). It's OK but still not too great.

kinetic (Steve) · #3 25-01-2009, 02:48 PM

Thanks renormalised!

As I said, I'm certainly no LRGB expert

When doing the blue channel I noticed it was poor and just
assumed that Cent A 'just don't have a lot of blue in it'

When it came to the LRGB combine, I realised that I needed to
disable back the Red and Green to get the Blue to contribute
to the image. Sorry for the feeble , non scientific,
cave man descriptions here

I tweaked them until they looked right and didnt destroy the Lum detail
then clicked apply.

Hardly a good routine eh.....
I wish I could somehow upload the 4x LRGB FITs files and let people
show me how it's done...but they are 3.5M each!

Thanks so much for the advice,

Steve

renormalised (Carl) · #4 25-01-2009, 03:51 PM

That's OK....it wasn't so much the advice as it was just playing around with the finished product to see what I could get. Like you said, the best way to repro this would be to do it from scratch with the .fits files

Have another go at Cen A, but this time make your subs 15-20 secs long, and give yourself a bit more luminance as well. Try unsharped masking to bring out the detail.