I have had some very intriguing issues using a UHC /LP filter.
When I used it with my ED refractors, the only issue is blueish stars, but NICE high contrast. When I tried it with my fluorite refractor, I get WOEFUL, globular, pixelated messes of images - yet without, they are FINE. I have NO IDEA why, unless just the difference between ED and Fluorite glass????
Anyway, here's B33 I did with my beloved fluorite Vixen 102 refractor from light pollution central a little while ago - only 5 x 5 subs.
http://imageshack.us/f/441/horseheadnebula2.png/
Minimal processing - mainly to remove the dust mote "blobs" (they were on the DSLR sensor platen)