Posted 13 December 2007 - 06:20 PM
Excellent! You should put the IDA (International Dark Sky Association) Logo on the shield!
You are completely correct about playing with the brightness and contrast, it will darken the backround but I will loose the spiral structure.
My SQM read 20.6 and my skies are fairly dark, but at the longer exposure settings which I need for the faint stuff, I get that type of lighter backround. I can darken it by playing with the histogram on most images, but here I would have lost the spiral structure since it is so faint.
I think a light shield opposite the focuser would help but what I needed last night was a shield for the WATEC which was mounted on the UTA, the camera picked it up and washed out some images that could have had more contrast.
I think I can benefit from the filter but the more light pollution, the better that filter will work.