I was imaging the other night with my 150mm F5 Newtonian and whilst waiting for some high cloud to clear I thought I would see what sort of image I could get with my Canon 600D DSLR, 2" Baader UHC-S L Booster filter and a 102mm F5 achromatic refractor. I left the coma corrector in for the shot with the Baader filter. These are single shots.
I was surprised and pleased by the result considering the cost of an ED or APO scope. I also tried the combination on the Rosette and Horsehead and got some good results. I also tried the Baader Semi APO filter and in my opinion thought the UHC-S filter was a bit better.
I'd be interested in other people's experience with filters and achromats.
RichardJ
