Quote:
Originally Posted by astro744
The view is only as good as the lowest common denominator.
Note I did not equate cheap with bad so my Boolean algebra still applies.
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Your "logic" implies that both objective and eyepiece contribute the same amount to image quality, which is very, VERY far from the reality.
Objective must deliver the wavefront with unbelievable precision; in case of a good planetary telescope, the maximum allowable wavefront error is in order of 1/10 wave (~1/20 on the optics). The eyepiece's task is to only magnify this image and deliver wavefront that is contained within eye's ability to resolve (which is several arc minutes). In case of planet observation, this condition has to be met only on axis (and near it).
Virtually
ALL eyepiece designs that you can buy today will satisfy this condition. All of them. In other words, eyepiece tolerances are many thousands, if not millions of times more loose than those for objective side of the telescope. Good mirror or lens is made by a master optician and travels many
many times from polishing machine to testing apparatus and back, often tested on the sky (star test) or interferometer before it is declared good enough. Eyepiece lenses are made in bulk by automated machines with no testing whatsoever of its optical surfaces (yes, even those at Zeiss and Leitz).
Have a look at on axis spot diagrams for eyepieces in Rutten and Van Venrooij's book (or more recent Smith, Ceragioili and Berry). All of them are virtually indistinguishable on axis. What you pay in a premium eyepiece is its off axis performance, first and foremost, and then we can talk about quality of polish and coatings. And those last two items make just about 1% or so of the total performance on planets.
Seeing differences in scatter (which will be the
ONLY visible difference between your cherished Zeiss and my non brand Ortho on planets) is, as said before, not easy, and definitely not obvious. It requires special object, near perfect seeing and lots of patience; again, I
have done this comparison, many times over the last 40-odd years. In refractors (yes, premium APOs as well as observatory class refractors like 24" and 20" Zeiss), reflectors (yes, premium reflectors with mirrors by LOMO, OMI, Suchthing, Zambuto, Galaxy, Lockwood, Barry Adcock, my own, and many others), catadioptrics (Maksutovs, SCTs, Wrights) and compound exotica (Schiefspieglers, Schupmanns) with same results.
Unless we talk about things like apparent field of view and off axis perfromance (which is totally irrelevant for planetary work), differences between eyepieces
on axis are always going to be very, very small.