Fred wrote: > > > ...you'll have the equivalent of a f16 400mm with any if these > > converters
> Well, a 2X TC used with a K 200/4 would give you 400mm at ~f/8~ > (but, of course, you would then usually stop down, if possible). > > Fred That's one of the real problems with TCs, isn't it. If you need the sharpness of your prime lens, which is usually best at least 2 stops from full open, that will not be averted by the use of a TC, but the 2X or 3X exposure increase forces you into a very dark, hard to focus viewfinder situation. If you're really lucky to possess a lens that performs well at close to maximum aperture, make a note of that fact! "Okay to use with TC!" keith whaley
