Does anyone know if there is a manufacturer of Night Pollution Filters in 82mm? I can only find such a filter for my telescope, none for any lens.
nubu said:I think you mean Light Pollution Filters? The later are interference filters and quite costly in bigger sizes, so typically a good one for 2" is 200US$! For this very reason Astronomik is producing clip in filters for Canon FF and APS-C bodies: http://www.astronomik.com/en/photographic-filters/cls-ccd-filter.html They work very well and I use them a lot for all my primes from 14 to 500mm ...
nubu said:It is true that clip in filters cannot be used with EF-s lenses because of their prodruding lens elements entering deeper into the body!
"you do need a longer exposure to get excellent results" I dont understand. That may be true for any filter you put in front or behind your lens and is NOT specific for clip in filters.The clip in filters have exactly the same effect of filters you would screw into your telescope...
One thing to note is for ALL interference filters is that their effect is light angle depending (because of the many layers they consist of and which have the wrong separation when looked at in a tilted manner)!. A consequence of this is their possible unevenness for wideangles when using them in front of the lens and for low focal ratio lenses when used behind the lens. Especially narrow band filters for e.g. Halpha should be bought somewhat broader when used in fast systems! The manufacturers state such limitation in their description!