Quote:
Originally Posted by mandragara
I have a fairly fast f/5 Dob. Considering getting one of these Fujiyama eyepieces to see what this famed sharpness is like.
Does using a Powermate style focal extender compromise their sharpness? To me a 25mm Ortho + a 5x focal extender for planetary viewing might be the way to go.
I'd be comparing it to a 25mm Televue Plossl, do you think the difference would be noticeable? Or are the TV plossl's just too well corrected?
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The 25mm works very well on my f5 dob. I haven't tried it with a 5x extender, but I can't see any issues. Remember though that the view can never be better than the weakest link in the optical path allows, so if it is a lower quality extender the view will reflect that.
I doubt that you would see much difference compared with the TV25, apart from a slightly smaller field. The Fuji may offer slightly higher contrast. I don't have the TV25, but I have a TV32 which is excellent; although certainly not any sharper than the 25mm Fuji, which remains my favourite for clarity of the view.
One thing is for sure, you wont have any problem with eye relief! As noted before, this design usually has better eye relief than the plossl design; and in this case it is 22mm vs 17mm for the TV. This will be even greater when mated with a barlow.