Product Description
This Astro-Tech ED refractor has:
• 102mm f/7 fully multicoated FCD-100ED and Lanthanum doublet refractor optics
• dual-speed 2.5" Rack and Pinion 2” focuser with 10:1 ratio fine focusing and built in Camera Angle Adjuster (Same mechanism as our EDT series)
• 2” and 1.25” non-marring compression ring accessory holders
• Vixen dovetail plate with two tube rings and a carry handle
• retractable self-storing lens shade
• .95 Strehl ratio minimum
• long-lasting white finish with Aston Martin Grey focuser and trim
The new Astro-Tech AT102EDL is an extension of the beloved 60ED and 72EDII. This scope is for the person wanting a little more than what the 60ED and 72EDII can bring to the table.
The important performance updates come in the type of ED element combination and the type of focuser the AT102EDL is built around. The new AT102EDL has upgraded the ED element to FCD-100 with a Lathanum mating element. Our first star test on the AT72EDII prototype was simply textbook. A perfectly defined set of white diffraction rings with jet black spacing. As this is an extension of that philosophy I know the AT102EDL will preform just as well. The next upgrade comes with the 2.5" Rack and Pinion focuser with 10:1 fine focus knob. It is the same mechanism as our EDT line and is buttery smooth. The focuser also comes with a built in Camera Angle Adjuster to help you get just the right position for your camera or diagonal. The final upgrade is something that people have asked us about for years...a simple carry handle. The ergonomic handle mounted on the top of the tube rings will make setting up a breeze.
This 23.6” long refractor optical tube could be all the refractor you will ever need. Its combination of aperture, glass type, and build allows the scope to be a fantastic visual instrument as well as a great photographic instrument. A good 4" refractor is hard to beat most nights for pure visual enjoyment. The supplied Vixen style dovetail fits directly into the dovetail slot on the top of many altazimuth and German equatorial mounts, such as those from Astro-Tech, Celestron, Meade, and Vixen. The OTA weighs in at only 9.3 pounds with rings and dovetail.
Features of this Telescope . . .
AT102EDL doublet refractor optics: 102mm (4”) aperture, 711mm focal length, f/7 focal ratio air-spaced doublet lens using premium FCD-100 ED (Extra-low Dispersion glass) with a Lanthanum mating element to reduce spurious color halos and fringing to vanishingly low levels with a .95 strehl ratio minimum guarantee. While we do not claim fully apochromatic performance in the class of a multiple thousand dollar Takahashi (this instrument is a sort of homage to the FS102), Astro-Physics, or TMB refractor, the AT102EDL is so free from spurious color as to be virtually indistinguishable from an apochromatic system. And, as Mr. Spock probably said in one episode of Star Trek or another, “Any difference that makes no difference, is no difference.”
Multicoated optics: The objective lens has the latest state-of-the-art broadband antireflection multicoatings on all four air-to-glass surfaces for high light transmission and excellent contrast. This can easily be seen by looking into the objective lens of the scope. Virtually no reflection of your face will be seen. It’s a sure sign that the high transmission coatings are doing their job, by letting virtually all the light enter the scope, rather than reflecting some light back to your eye.
Internal light baffles: There are multiple contrast-enhancing knife edge baffles inside the optical tube, and Micro Baffles running the full length of the focuser drawtube, for truly dark sky backgrounds and high terrestrial contrast. In addition, the edges of the objective lens are blackened to eliminate contrast-reducing stray internal reflections.
Dew shield: A self-storing retractable dew shield slows the formation of dew on the lens in cold weather to extend your undisturbed observing time. It also improves the contrast, similar to the effect of the lens shade on a camera lens, when observing during the day or when there is excessive ambient light at night, such as a neighbors backyard security light. The dew shield is 120mm in diameter
Dual speed microfine 2.5” Rack and Pinion focuser with 1.25” adapter and a built in Camera Angle Adjuster: The precision-made 2.5” focuser has dual-speed focusing. There are two coarse focusing knobs. The right knob also has a smaller concentric knob with 10:1 ratio reduction gear microfine focusing. This provides exceptionally precise image control during high power visual observing or critical DSLR or CCD imaging. The focus knobs have knurled gripping surfaces so they are easy to operate, even while wearing gloves or mittens in cold weather. The focuser drawtube has a scale marked in 1mm increments so you can note individual focuser positions for easy return to the correct focus when switching between visual use and photography. A lock knob under the focuser lets you lock in your photographic focus.
The focuser drawtube terminates in a 2” compression ring accessory holder to accept a 2” star diagonal and 2” photo accessories.
The supplied 1.25” accessory adapter slips onto the 2” accessory holder and uses a soft brass compression ring to hold 1.25” star diagonals and photo/visual accessories in place. The 1.25” and 2” compression rings won't scratch the barrels of your star diagonal or accessories as an ordinary thumbscrew can.
The AT102EDL now comes with a nylon soft carry case with room for accessories. This case not only protects, but will help you get out to the field with ease.
Tube finish: The optical tube is finished in a white powder coat with Aston Martin Grey trim and housings.
Other supplied accessories: A slip-on metal dust cap is standard, as well as the CNC carry handle. Two threaded holes for installing a finderscope mounting bracket are located on the upper left and upper right side of the scope body.
Tech Details
| Aperture | 102mm |
|---|---|
| Focal Length | 711mm |
| Focal Ratio | f/7 |
| Heaviest Single Component | 9.3 pounds |
| Weight | 9.3 pounds |
| Optical Coatings | Fully Multi-Coated |
| Telescope Type | Refractor |
| Warranty | 1 year |
| Back Focus | 161mm |
Reviews
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)
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)
(Posted on 3/30/2023)
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)
I own two other apo triplets and this jewel is every bit as good. I highly recommend this scope. (Posted on 3/5/2023)
