We can discuss optical quality, aperture, and price until we are blue in the face, but what it comes down to is the view. When we say that "all else being equal, aperture wins" we have to realize that all else is NEVER equal. I sometimes(about 30%) use my 12.5" reflector stopped down to 4" because the view is better to my eyes on some objects under some conditions. Since the scope is identical optically(no obvious zonal abnormalities), why should I prefer the "inferior" smaller aperture? Also sometimes I use my 5" goto SCT for convenience and sketching and my 4" APO for double stars, etc. You just can't factor the observer into, or out of, the equation.
The view is the thing
Started by sthater, 07/15/2003 03:57PM
Posted 07/15/2003 03:57PM
Opening Post
Posted 07/15/2003 04:54PM
#1
Bravo Stacey. You've brought back sanity to the discussion ;-) Very well prosed! Just this morning, I had to use my 4" TV-102 instead of my 8" PDHQ because of *impromptu* Mars observing and the 8-incher just wouldn't cool down in time (maybe the fan will help) and the seeing was very good!
Ron B[ee]
Ron B[ee]
Posted 07/15/2003 05:52PM
#2
"why should I prefer the "inferior" smaller aperture?"
I dunno because I never do. I have a 4" off-axis aperture mask for my 10" Teleport. Oh, yeah, the view is constrasty and there are no diffraction spikes, but Airy disks are huge by comparison. It lasts about 5 minutes, then the mask comes off. When you talk about factoring the observer into or out of the equation, you really must mean the individual observer, i.e. not an observer in a generic sense.
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Mike
I dunno because I never do. I have a 4" off-axis aperture mask for my 10" Teleport. Oh, yeah, the view is constrasty and there are no diffraction spikes, but Airy disks are huge by comparison. It lasts about 5 minutes, then the mask comes off. When you talk about factoring the observer into or out of the equation, you really must mean the individual observer, i.e. not an observer in a generic sense.
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Mike
Funding Member
