I have a humble AT80EDT, an f/6 triplet with FPL-51 glass. I love it, but aperture fever eventually set in and I began to look for a larger refractor to replace it, settling on the Explore Scientific ES102CF--the carbon fiber version. I found one in the classifieds and pounced.
Unfortunately the scope was disappointing, and I returned it, gaining a lot of appreciation for my little Astro-Tech in the process.
The AT scope's mechanics are just so much better. Its R&P focuser is way nicer than the Crayford on the older ES scope. It's smooth, doesn't slip, has plenty of travel to come to focus with all my eyepieces without needing any extension tubes, and it has nice big knobs made of anodized aluminum. The AT's dew shield is solid and snug, doesn't wobble, and the anodized aluminum lens cap goes over the dew shield. The AT's tube rings are also anodized aluminum, and the tension knobs are large and easy to use. The AT uses Vixen-style finder mounts. The ES, by contrast, uses painted stamped steel for the lens cover and tube rings, the lens cover and dew shield are wobbly and loose, and it uses those little uncommon Meade finder scopes mounts.
Optically, the AT seems to punch above its weight. Despite the fast focal ratio and FPl-51 glass, I can detect no CA anywhere even on high magnifications of bright targets like Venus. Views are razor sharp. The ES scope by contrast showed some CA on Venus and Jupiter despite the slower focal ratio. Views were also mushier due to some unspecified optical defect in the scope which is one of the reasons why I returned it. But still: that FPL-51 glass in the AT ain't no slouch! Another thing: internally, the ES scope had one light baffle; my AT must have about 15. The attention to detail is just pretty impressive.
All of this makes me want to buy another Astro-Tech telescope the next time I feel like upgrading. The 102EDL looks amazing; my only hesitation is that I'd prefer a triplet in f/5 or f/6 for a shorter tube length and to make better use of the nice eyepieces I've already bought for my 480mm focal length scope. But it seems like for that I will have to save up for a super-expensive Tele Vue, APM, CFF, or Borg, or sell a kidney to win a bidding war over a used Astro-Physics Traveler. Would probably be cheaper to re-buy new eyepieces better suited for the 700mm focal length...
The bottom line is that I really like my AT scope, and I appreciate how Astronomics is able to sell telescopes that get so many things right for such competitive prices.
Edited by pointedstick, 15 September 2021 - 07:45 PM.