Astro-Tech AT102EDL Refractor OTA FCD-100 and Lanthanum f/7 Doublet

I picked up one of these late last year to be a travel scope. It checks all the boxes that you expect from a frac. Stars are diamonds on black velvet. There were no cosmetic issue with mine and mechanically it functions as it should. I will admit i am impressed with how it does on the moon and the image it returned of the Ring Nebula was beautiful. A word of warning to those of you who are used to light buckets, this scope can't even start to match their light gathering capabilities. For my wife and I it will serve us well as a travel scope. (Posted on 1/6/2024)

High quality parts throughout and precise images. Large 4" objective pulls in faint fuzzies, and works well with its optional Reducer/ Flattener. You cannot find or beat this quality scope anywhere. Camera rotator and quality focuser. I've taken many astronomical photos with mine with great results (pulls in more light than smaller scopes can provide). I completely forgot to check (again) for Chromatic Aberration (CA) as it does not exist with this scope. This scope is a good size to transport (even to backyard), yet large enough glass to pull in great images. You can find no more detail on the internet... believe me, i've looked, and no one exceed the Astronomics service. Packaged extremely well and shipped quickly. A great buying and using experience. (Posted on 10/3/2023)

A truly perfect little 4", nicely complements my 8" and 12" Dobs . I bought one used last year, then sold it (as I wasn't doing much visual at the time), regretted selling it, and picked up another during the $999 sale. Outstanding value for money. For quick sessions, I prefer the portability of the 102 over my much heftier AT130EDT.

The mechanics and finish of this scope are unimpeachable, and the views are excellent. No obvious false color seen on a last quarter moon at 238x. I'm hanging on to this one this time around! (Posted on 4/8/2023)

I had been looking at this scope for a number of months – before it went on sale for an even lower price, and then my tax returns came in. At that point I had no excuse not to buy it anymore. Since then I have had several opportunities to take it out, and it is as good as it claims to be. I have not been able to find chromatic aberration either visually or photographically (although I can see a hint of red if I am slightly not in focus). The optics are sharp, at least so that at 200+ magnification the stars form very nice airy disks with maybe one or two rings if brighter than 1st magnitude. How this telescope does not have “APO” in the name I do not know. Unfortunately Jupiter and Saturn are not visible right now, and Venus and Mars do not have much detail for a 4” telescope to observe, so I cannot comment on planetary contrast; however, deep-space-objects I observed (the Orion Nebula and a globular cluster) show very well in this telescope, as do (open) star clusters. I spent some time splitting Rigel, Algieba, Castor, and a few other double stars as well, and all of them look excellent in this telescope (especially Castor).
For optics, I would rate this 4.5-5 out of 5 stars – for those technically inclined, it does seem to have a hint of spherochromatism, although this is to be expected of an APO or near-APO doublet, which typically shows up as some blurring if outside of focus. For those not technically inclined, don’t look through the telescope out-of-focus. It does have very nice rings inside of focus, produces a clean image, and my copy came in excellent collimation.
For the focuser, I would also rate it 4.5-5 out of 5 – the focuser is excellent, easy to use, holds focus well, and allows the user to rotate it (and a camera or diagonal) to a better angle for ease of use. However, having the ability to rotate the focuser introduces a small amount of slop – this is true of nearly all rotating rings – and should be noted. In practice it had little impact on image quality or usage other than needing to realign the finder scope (mounted to the focuser) I was using periodically.
Overall I give this telescope 5 stars. Any improvements would require spending at least double the cost of this instrument to obtain.
(Posted on 4/4/2023)

I bought this from Astronomic and it a great scope. I do imaging mostly . The optics are fantastic. Verry good quality. Great place to do bisness with. Cherokee
(Posted on 3/30/2023)

I took the plunge and purchased an AT102EDL on Friday, 3/24/23.
With Ken's fantastic turnaround and some divine intervention the scope arrived on Sunday, 3/26.

Even better, it was clear skies on 3/26, 3/27 & 3/28!!

Anyway, I was on the fence about this scope for a number of reasons. Did I really need another scope? Was it going to be worth the price premium over a 102ED? Should I instead get a TS 102ED F/11? Should I go more premium with a Tak? Etc.

Well, the sale price convinced me, and I'm glad I did it.

FWIW my sample is, to my eyes, great. No mechanical or cosmetic problems. I mounted it on my Skyview Pro mount and started testing. Collimation was good in the star test. One side of focus shows great diffraction rings, the other was a spherical blur. Not too concerned about that, and I did the test through a diagonal so not definitive. I will eventually check collimation with a Cheshire, but I don't expect to see an issue. Stars come to focus as an airy disc which seemed uniform enough given the conditions. Coming to focus did involve a bit of 'wibble-wobble' in opposing axis, not a perfectly spherical shrinking to the disc, but nothing too evil looking. Anyway, enough clinical stuff, how are the views?

First up was the moon, my old friend. Seeing seemed average improving to good during the session. Did some prelims with a Baader 8-24, then switched to my Orion Bino with 18mm BCOs and a TV 2x Barlow. Really solid views, and I was starting to think the optics were better than good. Then I switched back to the Baader + their 2.25X barlow. I was shocked by the image scale, everything was huge! Turns out I had left the TV 2X in place. I ran the scope all the way up to top mag of ~400x and learned a few things:

1. My eyepiece was dusty;

2. I have a lot more floaters than I thought;

3. The seeing was better than I estimated and/or there is something to a 4" aperture being in a 'sweet spot';

4. I could see things at 400X that I did not at ~200X - I know this is 'empty magnification', but it still made a difference for me;

5. The optics in the scope were better than good, I've never had a scope that would eat mag like this before.

False color was well controlled even at stupid mags.

I also took a look at the Pleiades, the Hyades and the Orion Nebula. Jewels on black velvet & in cotton candy, etc. All the standard refractor language applies.

Over the next two nights I viewed the moon again and the results have been the same. Clear Dark Skies said Poor to Average seeing and I was cranking up to 300-400x both nights. (CDS is calibrated to an 11" scope, so ratings are conservative/low for a 4" I think)

Last night I double barlowed the binos (2X nosepiece + 2X TV) and saw things in Hyginus - like detail in the highlands to the north of Rima Hyginus as well as the full extent of Rima Ariadaeus - that I have never seen before in any of my scopes. I'm considering adding a TV 3X Barlow and 5X Powermate to my toolset for these lunatic excesses of magnification!

In the end, I give this scope a strong 'buy' recommedation. For these purposes - high mag and stupid-high mag - the quality of the optics was really worth the price IMO. I don't think my 6" GSO Newt is going to be seeing much moonlight for a while. (Posted on 3/29/2023)

The best value in refractors. The optics are stunning and it peforms as awesomely as my friend's 100mm Takahashi, for a quarter of the price. No chromatic abberation, pinpoint stars, beautiful Airy disks at high power, crisp planetary and lunar views. The scope is built like a tank and the two-speed focuser is ultra-smooth. Objects snap into focus. Even the retractable dewshield is cool. Everything I wanted in a premium refractor. 100% satisfied. (Posted on 3/25/2023)

Fit and finish are way beyond my expectations. Views are crisp and bright with no chromatic aberrations. Simply everything you could want in a 100mm F7.
I own two other apo triplets and this jewel is every bit as good. I highly recommend this scope. (Posted on 3/5/2023)

First off the build quality is excellent. After a couple imaging sessions it was apparent this is closer to a triplet than a doublet. Stars don't have halos, except super bright ones and they are not bad at all. I imaged the Veil Nebulas and the definition and color is awesome. I use an L-extreme filter for nebulas. I would highly recommend this model if you are considering it instead of a triplet.... (Posted on 10/6/2022)

I've had a few chances to observe with this beautiful telescope and I must say it's tremendous! The build quality is fantastic and the optical performance is absolutely first rate. This scope really performs. If you are thinking about this telescope or the AT102ED, know that the 102EDL is a cut above. The AT102ED is excellent but this telescope with the FCD-100/Lanthanum lens combo is better and I don't think it takes a back seat to any of the great 4" refractors out there. I also think the sale price of $1079 is a true bargain. Another thing I really like is the rotating focuser. It makes aligning the eyepiece and finder scope so much better. Highly recommended. (Posted on 7/4/2022)