Chuck, I have used the Naglers on my 8" doublet refractor (f13.3). I have also used the orhtos. I have never compared the two. I'll do that. Your 10" is more sensitive to collimation errors. The quarter wave circle for your 10" is only 1/8 inch in diameter, while your 6" quarter wave circle is .358". This means that the six inch has a quarter wave field of almost 26 minutes of arc. The 10" quarter wave field is only 7.5 minutes of arc. This is probably a part of what you are seeing. The 10" has to be aligned much better to see the smaller sweet spot. Brent --- Chuck Hards <chuckhards@yahoo.com> wrote:
Isn't the TeleVue refractor line in the f/7 range? It makes sense that TV eyepieces would complement TV refractors.
Brent, what do you think the Naglers would do on the Clark or other large, long doublet? I think the programs that plot spot diagrams do so for only one wavelength, don't they?
I admire you're use of slower objectives. We're on the same page here for sure. While it doesn't have the resolution of my 10" f/5.6, my 6" f/8 is much more contrasty...much less diffraction, almost a "cleaner" image...does that make sense?
C.
--- Brent Watson <brentjwatson@yahoo.com> wrote:
My 12.5 is not a fast dob. It is f7.5. My problem with Naglers on the 10"f10 is one of internal reflections.
Since I got my Naglers the orhtos have gatheres a bunch of dust. That will change.
Brent
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