Quote:
Originally Posted by alistairsam
Hi Justin,
You are getting some nice results but this one I think needs more data and less blur as it doesn't show much structure, just my opinion and I'm no expert.
Are you able to retain the 12 bit format while editing? I know 4 bits aren't too much but it could enhance transitions in subtle areas.
for eg, 12bit to 16bit does have quite a difference in the number of shades of gray.
PS CS5 supports 16 bit, so I presume would support 12bit native.
also, i'd suggest against using gaussian blur and to instead use dithering and darks to remove noise. the blur would remove a fair bit of contrast in areas with sharp transitions. dithering and darks are very effective with noise reduction.
this was an image i found with 5x20min subs with a cooled dslr so not a straight comparison, but i just wanted to highlight the dark areas that make details stand out if you know what I mean.
http://www.centralds.net/cam/?p=2269#!lightbox[auto_group1]/0/
Look forward to more.
Cheers
Alistair |
Hi Alistair,
Thanks for your input.
I'm running PS7 which is quite old, it will only allow me to have full control of the image in 8 bits and partial control in 16 bits. So most of my processing has to be done in 8.
Your right about more data, but this DSO never gets very high in the sky and was at a maximum height of 25 degrees when imaged. So I'm not going to acheive the detail that someone in the northern hemishpere.
I'm using darks, flats and bias frames, but until I have the camera cooled noise is going to be a problem in warm weather.
I will try dithering though.
I have done another repro here.
I used a little more black in reds and magneta in selective colours, also 15% more contrast on the nebulosity.
It has helped a bit.
Cheers,
Justin.