David Cotterell Toronto, Ontario "If an observer actually sees an object, there is no point in referring to a formula to find out whether he ought to see it; and if he fails to detect it, no formula will ensure his success." - W.H. Steavenson 8" f/15.5 TEC Maksutov - 16" f/5 Teeter/Zambuto Dob - TEC 140 - AT 65EDQ APO Refractor - Astro-Physics Mach 1 GTO Mount - iOptron ZEQ25 mount - Discmount DM6 - Canon 60Da
Uncle Rod Uncle Rod's Astroblog: http://uncle-rods.blogspot.com/
Quote:Sigh...2-inch eyepeices work just fine with an f/6.3 r/c...
Quote:Sigh ... "Many" 2-inch eyepieces work just fine with an f/6.3 r/c...
Quote:Hi, Rod.Well, it works, but "Fine" implies that there is no damage to the image.
Quote:Quote:Sigh ... "Many" 2-inch eyepieces work just fine with an f/6.3 r/c... ... but some don't. There isn't enough focus travel with some 2" eyepiece/2" diagonal combinations on some SCTs when using the r/c.
Quote: Quote:Sigh...2-inch eyepeices work just fine with an f/6.3 r/c... No vignetting with the 41mm Panoptic the F/6.3 RC hooked up to a C-8?Jon
Quote:There are quite a few similar scopes that focus at the eyepiece.Most classical Cassegrains, and things like the Vixen VMC200L have fixed mirrors. You give up the advantage of flexibility with accessories (hugh range of back focus) but gain in optical performance from the optimum mirror spacing. There was an article in ATT a year or two ago that discussed the resulting optical errors away from optimum spacing.Also, it's easier to incorporate collimation adjustments to each element, unlike most SCTs that adjust the secondary only.
Quote:I, like many other folks, have been using 2-inch eyepieces and 6.3 r/cs for the last twenty plus years and...yes... the combo works just fine.