Details.
Canon 5DH, Canon 300mm F2.8L at f/2.8, Hutech LPR filter. ICNR ON.
This image is the result of using EasyHDR on five sets of exposures, consisting of 5X(1&2 minutes) at an ISO 200, 5X(2,4 and 8 minutes) at an ISO of 400.
I did not have to use GradientXterminator and you will notice M4 is not blown out.
Bert
Had another go at this difficult region.
This time 9x(1M, 4M, 16M) at an ISO of 500 and the fridge cooling the 5DH at -5 deg C. I think I can safely go lower in temperature as the camera was still warmer than this about 8 deg C by a quick measurement on removing the fridge. I put the thermistor into the battery compartment.
Large image 1.3MB http://members.optusnet.com.au/~trlee8/rho_oph2.jpg
The real problem here is to get the colours to show clearly, the noise is not far behind.
I will keep trying!
Meanwhile enjoy in spite of the noise.
The real problem here is we are trying to record scattered light as opposed to the usual emission nebulae. Those brown and black things are clouds of dust. The coloured bits are the same dust clouds illuminated by 'nearby stars'.
By the way we are all made of these clouds of dust!
Well framed Bert. It is difficult to reach the right colour balance in this area. By the looks of your second image, R and B are very dominate - increasing green will address this, but you may loose some nebulosity. Layering will circumvent this. If you're using secondary colours, increase cyan and yellow (as it absorbs red and blue respectively). You will know when you hit the right tone as the global cluster M4 will appear white.
Thanks for the comments. I had another shot at processing the data from scratch while not so tired from collecting it. It is hard to be careful at 0400 HR.
Thanks for the info in which direction to head in Jase. Maybe We could put the 60MB tiff up on IIS server for people to play with.
It is difficult to reach the right colour balance in this area. By the looks of your second image, R and B are very dominate - increasing green will address this, but you may loose some nebulosity. Layering will circumvent this. If you're using secondary colours, increase cyan and yellow (as it absorbs red and blue respectively). You will know when you hit the right tone as the global cluster M4 will appear white.
