Using my Astronomik CLS light pollution filter, I found that my astrophotos were awash with blue. I could not process them correctly and especially with galaxies, I ended up discarding hours of work. After some helpful advice, I tried a 'custom white balance' on my Canon 30D by shooting a white card in full sunlight with the filter attached. I set that photo as the one to use as custom white balance, and Voila! Balanced photos.
The filter always did a great job removing light pollution, but now it's a snap to process the images.
You can see that the WB that I was using, daylight, is the absolute worst setting I could have chosen.
All photos in this folder are with the Astronomik CLS filter installed.
© Hunter Wilson