Meade 127ED vs ES127 vs 120ED
Posted 03 April 2013 - 10:09 AM
I've always heard good things about these scopes and their 4" little brothers (less so the larger 6" and 7" in the family, which I've read were less consistent). Has anyone compared one of these vintage Meades directly to one of the similarly-sized Chinese APOs?
I expect there'll be more chromatic aberration than in a modern premium triplet, or a long doublet using fluorite/fpl-53. But if defocused color is tolerable, and most importantly the figure is good, I'll be happy!
Posted 03 April 2013 - 10:31 AM
Posted 03 April 2013 - 10:32 AM
Meade documentation provides the glass types of both elements. Neither is FPL-51. From the product manual for these scopes available on Meade's website (still) the glass types are:
Objective Lens KF3; ED/FK01 KF3; ED/FK01 KF3; ED/FK01 KF3; ED/FK01
Optical Tube aluminum aluminum aluminum aluminum
Equatorial Mounting aluminum castings aluminum castings aluminum castings aluminum castings"
FK01 was the low dispersion glass-type used in the vintage Meades. It has properties similar to FPL-51 but is not FPL-51 which is an exclusive Ohara glass type. Hikari was the maker of FK01.
Comparison of FPL-51 and FK01:
FPL-51 Abbe Numbers: Vd = 81.54; Ve = 81.14
FK01 Abbe Numbers: Vd = 81.63; Ve = 81.22
So the Hikari glass has *slightly* better dispersion properties than FPL-51, though they are so close as to be immaterial in practice.
I used to own a 127ED doublet. It was a great scope so long as you manage to keep the elements centered and not tilted relative to one another. The focuser on mine failed after a few years so I replaced it with a Moonlite. All in all it was a wonderful visual scope, better figured and better corrected than a 5" f/10 D&G achromat I owned simultaneously, and not especially heavy or imbalanced for its considerable length.
For me the false color was entirely tolerable and the image quality excellent. The thing is, it's an old scope at this point. If you happen to get one that's been roughly handled it can be a frustrating self-help exercise to get it sorted out. The other scopes you mention have current availability and current support/warranty, and the price of them is not a lot different than the used price of a fifteen+ year old Meade doublet with no available support.
I like the scope, but there are a lot of qualifications given its age. Personally based on the landscape of the refractor market now I wouldn't pay more than $1100 for a very good condition example. Much more than that and you could buy new and have recourse if you happen to have issues.
Posted 03 April 2013 - 11:41 AM
I got it for $850 plus S&H, at "the other place." I wasn't even looking for this scope but for that price I had to try it. At the very worst, it's similar enough in size and weight to my "dream scope" TEC-140 that I'll be able to try mounting options, and generally explore how much I like handling and observing with a refractor of this scale before making the big $$$ commitment. At best, it'll be a scope that I'll enjoy for a long while.
I've read that Meade used to offer cleaning and collimation on these scopes for a reasonable fee, and if it's in need I may check that out.
Posted 03 April 2013 - 01:21 PM
I'd say that is a very good deal. Refractors become "only" and "see everything" scopes at about 5-inches. That's where the "lights go on" compared to 4" and 3" apertures.
Posted 03 April 2013 - 05:49 PM
The tube is very long and the scope needs a good mount,
Atlas class and the focuser is somewhat hard to deal with.
I wanted to keep mine but the stock focuser was not held on with the typical (3) screws mine was either press fit on or clued on and I decided to re sell and not mess with it, but optically I have had (1) 127ed and (2) 102ed in the older Meade doublets and they were all nice, good luck