Click here to create one. 67 (ex. I purchased one, but it is back ordered till February. I have for sale a Sharpstar 60ED refractor. 25" · Optolong H-Alpha 7nm 1. The Altair Astro Starwave ASCENT 70 ED is a solid option for travel and wide-field astrophotography. Astro-Tech AT72EDII Refractor OTA FPL-53 f/6 $469. We all have questions from time to time. 8X Reducer for 60ED (ATRF60) Software Adobe Photoshop · Pleiades Astrophoto PixInsight · Steffen Hirtle GraXpert Guiding. Reviews. The camera side of the reducer uses 48mm T-threads to connect to a T-ring and camera body. With its retractable dew cap pulled in, its overall length is just 34 inches, but extending the cap fully makes it a bit longer than the Orion scope. The sleeve between the flanges is what affords the full 360˚ rotation of the focuser. VAT). Formal-Garden-7412 •. I like both the build and look of it, and the functionality of the rack and pinion focuser, but Im having a problem that Ive never experienced. 8X Reducer/Flattener + Williams Optics Guidescope package. The Altair Starwave 110ED-R refractor is a fantastic portable telescope that delivers detailed views at an enjoyable resolution. While this Astro-Tech ATRF72 0. Astro tech 60ed . 92 (ex. Theres two mounting screws on each side of the scope. Parameters: Size: 59mm x 52mm x 41mmAT72EDII vs SV503 70ED - posted in Beginning Deep Sky Imaging: Im looking for a small portable refractor to get into AP and Im currently looking at a used AT72EDII or a new SV503 70ED, both include field flatteners. VAT) Out of stock. Astro-Tech 60ED Review So very dinky. Theres two mounting screws on each side of the scope. The Astronomics listing for this. Resolution Formula: ( Pixel Size / Telescope Focal Length ) X 206. Spencer-3D. - Astro-Tech AT72EDII f/6 - Explorer Scientific 80mm f/6 ED I don't want to spend too much budget on astronomy yet, i will not buy so expensive high end gear so i will keep myself in the intermediate or entry level if necessary, that is including the refractor as well, that budget i think it is in entry level to intermediate level, above $3000. The TV-85 is a great scope for astronomy with it's increased light gathering but too big and heavy to carry. 265. 9)^2, or 0. Hopefully someone here has. . 20. $139. The Astro-Tech reducer/flatteners thread into the focuser for a solid connection. There is no comparison with the default Synta focuser. ZW Optical. My goal in purchasing the Astro-Tech 60ED is to have a very portable scope that lets me take moderately closer glimpses at deep sky targets of interest to me. 8x CCD Telecompressor for 92mm Stowaway and 105mm Traveler. 6- Altair Starwave Ascent 102ED F/1122 - The planet killer outstanding high magnification performance. 00 usd. Most other 80mm apos Ive seen are much more expensive, but the Astro-Tech is nearly. 8, and after a lot of Googling, including a long look at Astro Bin, I went with the Sigma 180mm f2. AstroBin is an image hosting platform and social network for amateur astronomers and astrophotographers. + FREE Shipping. . William Optics Adjustable Field Flattener For Zenithstar 73 £209. 80mm. This Astro-Tech AT102ED refractor has: • 102mm f/7 fully multicoated doublet optics using FK-61 ED glass. If want a proper mount, I suggest to purchase a fully manual altazimuthal one (good choices for a 60-80mm APO could be Vixen Porta, Skywatcher AZ4, Explore Scientific Twilight I, Astro-Tech Voyager). Posted 23 May 2019 - 11:05 AM. 0mm) > Camera (17. The rings have a 79mm internal diameter designed to fit the Radian 61mm refractor, but will also fit any refractor with a 79mm OD tube. View. You can image objects like the Heart nebula, Andromeda galaxy, Veil nebula and many more. UPC. Maybe try with 10 images at first instead of all 274. The camera side of the reducer uses 48mm T-threads to connect to a T-ring and camera body. My NIRQuest was easy to get up and running, but it seems like I can’t find the LabVIEW driver for the QEPro. (0. Astro Tech refractors diameters? - posted in Refractors : Hi all, I would like to know about the outer diameter of the following AstroTech scopes for something i want to buy, please make sure it is a precise measurement as much as possible possible. So, subtract the thickness of the t-ring from 9. 00 £165. 5). 8X reducer/field flattener is designed for prime focus astrophotography with the Astro-Tech AT72EDII, it will work with other variants of the same optical tube. Buyer take care of. 1. This is markedly higher reflectivity than the 88% of a conventional aluminum diagonal or the 96-97%. Views: 4822. Sky Rover 60 ED APO with field flattener. Starwave 60ED Imaging Refractor From: £379. ASTRO-TECH 60MM PHOTOGUIDE REFRACTOR "The new Astro-Tech AT60GS 60mm guidescope with upgraded helical focuser makes highly accurate autoguiding of deep space astrophotos affordable for any astrophotographer. 8x Reducer / Adjustable Field Flattener for GT71, GT81, Z81 & Z103. 25" · Optolong Green 1. 05167v2 [astro-ph. My first refractor. 00. Astro-Tech AT60ED 60mm f/6 FPL-53 ED Doublet $369. It uses two ED elements in its configuration and offers the unique flat field ability inherent with the Petzval design. A self-storing retractable dew shield slows the. 25" Accessories Astro-Tech . Astro-Tech uses two ED (Extra-low Dispersion glass) elements in the optical design of the AT60EDP. 8x reducer/field flattener for f/6 refractors is now available from stock. Obvious differences -- the AT 115EDT is a triplet apo, the SW 120ED is a doublet. Vostok 1. For the Astro-Tech Reducer/Flattener the spacing is 55mm with image circle of 42mm. Edited by BFaucett, 27 November 2021 - 01:16 AM. 95, 709mm FL, used Plossls of 32 to 15mm, and 66 degree ultra wide (similar to Orion Expanse) of 9 and 6 mm: M3 above Boo, nice fuzz ball at 20mm. The 2 inch focuser is extremely smooth and every screw has the non-mar. My goal in purchasing the Astro-Tech 60ED is to have a very portable scope that lets me take moderately closer glimpses at deep sky targets of interest to me. 00 usd. 8. I hope you guys will like it. There are three holes in the cap, similar to the circular holes in a Hartmann mask, that help you focus during imaging and visual use. Borg 60mm ED. Leo Triplet NGC 3628, M66, M65. The Starblast has a focal length of ~450mm vs 360mm for the AT60, so the Orion is capable of marginally higher magnification for lunar/planetary viewing. 2" aperture f/5 (530mm focal length) four-lens photo/visual system using two ED (Extra-low Dispersion) glass elements. F/5, 300mm. It will not work on all of them however. Brief Review: Astro Tech 80ED - posted in Refractors : Ive had this scope for a couple of weeks now and have used it on two occasions. com. And since we're a family business, we plan on being. This is a brand new 2019 item which is now in stock at Rother Valley Optics. 2 V. Astro Tech 60ED Telescope Review A miniature telescope with a specific task in its future, if I'm. We all have questions from time to time. If you get a. I was hoping to do this first light video of my Astro-Tech AT60ED after I got my flattener/reducer, however they just haven't been in stock. It is measurably the best no-compromise portable photo-visual refractor Takahashi has ever built, and they've built a lot of very good scopes over the years. William Optics Adjustable Field Flattener For Zenithstar 61 £209. I am. I own a TV-60, Astro Tech 60ED, and a TV-85. $139. The TS PhotoLine 60mm, f/6 FPL-53 apo arrives on the market amid some stiff competition from the suspiciously similar Astro-Tech AT60ED, the Altair 60EDF and the William Optics Zenithstar 61 apo (the Zenithstar’s 61mm, f/5. A few on the back. Page 1 of 4 - Astro Tech's new Scopes coming soon! - posted in Refractors : I didnt see this on the refractor forum. Takahashi FOA 60Q *Like New* 11/10/2023 05:03PM. Choose an option. Both WO refractors show exquisite but the price is expensive too, Sky Rover 60ED APO and WO Z61 looks no different to me but it is on a attractive price, the last AT65Q is already discontinued, but reviews are good. It seems like it’s similar, and yet quite a different design than their. Refractors. Thoughts on the Astro-Tech 80EDT? - posted in Beginning Deep Sky Imaging: Hi, Im looking to actually purchase my first personal astrophotography telescope (I have been borrowing one all this time). The Astro-Tech handle is not only nice to look at, it is extremely useful as it performs double duty. The foam conversion is not pretty but it safely holds the entire set up in a easy to carry case. Kind of a MkII. Not all apo’s are created equal. This finder shoe is designed to work on a variety of Astro-Tech telescopes. The Starwave 60ED becomes a fast astrograph at F4. This scope is for the person wanting a little more than what the 60ED and 72EDII can bring to the table. Anyway, I couldn't source a flattener for it but TS offer the Flat60 which is designed for their F5. 5" long with. Mechanically, the 2. 11/10/2023 06:06PM. I was very excited - until I opened the box to inspect my new telescope. 25-inch adaptor. Astro-Tech 60ED vs. I have been considering the Astro-Tech AT60ED 60mm and the Apertura 60mm FPL-53. Redcat 51 With ASI585MC. The important performance updates come in the type of ED element combination and the type of focuser the AT102EDL is built around. The MONARCH Fieldscope offers first-class optics and high contrast. The AT70ED's focuser can handle a binoviewer much better. Not as nice as the FeatherTouch. . 1-800-422-7876 questions@astronomics. Focal Ratio: f/6. Altair Starwave 60ED AstroBin's equipment database is entirely maintained by the community. The flattener produces wonderful flat fields as well as a 41mm image circle. 00. 8x field flattener (no stock currently) + William Optics 48mm T-mount for Sony E-mount OR 2. These include the Explore Scientific Twilight I, the Vixen Porta II, and the Sky-Watcher AZ5. (Ill add that itd be nice to have pleasant views of Jupiter, Saturn, and the moon, but no need for close detail. 8x Reducer Field Flattener For the 60ED Optical Tubes. New Astro-Tech 80ED - posted in Refractors : I had ordered and received a new open box SVBONY SV503 80ED which arrived with problems and was returned. Its fully multi-coated optics provide bright, clear images that are free from distortion and color. Stars are generally small with an even focused field across the QHY8. The SW 120 is slightly bigger. So until then I am stuck using scope uncorrected. Astro-Tech . The field is very large and with a focal reducer such as the WO 0. The new Astro-Tech AT80EDL is an extension of the beloved 60ED and 72EDII. Apertura 60mm APO Refractor Specifications. Astro-Tech AT72EDII. While I wait for astronomics to deliver my scope, I. In summary, we are using Nyquist as a starting point, with a slight tweak, because we are typically sampling very small, circular, stars. 00 £806. I have for sale a near new, recent vintage Astro-Tech AT60ED. Focal Length: 360mm. The equipment was mounted on a Celestron AVX GOTO mount. ASTRO-TECH . com. I highly recommend it. → Equipment Discussions. Back to top #7 nicknacknock nicknacknock. Of the remainder, two are vintage Japanese refractors and the rest are various American scopes. When adding an eyepiece or binocular, please don't include the magnification or aperture details in the model, this will get added automatically. This scope is the ultimate doublet refractor for those not wanting the weight and cool down of a triplet optical set. Altair's is almost the same name:Astro-Tech 60ED on Orion Tritech II tripod, StellarVue MV1 mount head: Maybe about a dozen pounds fully dressed? It is a true (for me) grab-and-go outfit, and can be carried outside and around the yard, as needed, with a couple of eyepieces in my pocket. Length: 18" dewshield retracted, 21. California nebula Astro-Tech 60ED test Equipment Imaging Telescopes Or Lenses Astro-Tech astrotech 60mm Imaging Cameras ZWO ASI1600MM COOL Mounts iOptron. Looks like a decent size scope I can hike with to remote locations and use with my Skyguider Pro with M4/3 and APS-C bodies, and its decently priced with its flat field corrector. The EDT triplet is surprisingly 2 lbs lighter and comes with a case. Chondrites (Carbonaceous) CI (Ivuna-like) CM (Mighei-like) CO (Ornans-like). FPL-51 or equivalent in the triplet. At 80mm aperture, this is a fantastic option for those wanting to spend their nights imagin. Celestron 2” xcel 5mm ocular $50. Everything is in good condition, no major issues. 8x Reducer Field Flattener For the 72EDII Optical Tubes. Keep in mind that the record for the tracker (afaik) is fullframe 600mm @ 600 seconds guided, which is stunningly good for such a small and portable system. Here are some Borg 60ED images resulting from a Google search :-Gary Honis-modified Canon XS(D1000), Hutech 60ED F3. The Astro-Tech 60ED is high on the list when it becomes available. Its color correction puts any achromat or so-called “semi-APO” to shame. As you add equipment to the view, the details will appear below. the flattener produces wonderful flat fields as well as a 41mm image circle. A super portable refractor telescope with FCD100 ED glass, suitable for astrophotography or visual use, day or night-time. I figure learn what Im doing, then. Astromelb. 5 to f/7 range that use a 2" focuser. It suffers somewhat from field curvature and the owner’s aging, less-than-accommodating. Both great scopes when coupled with the William Optics adjustable flattener. Sharpstar 60ED Astronomical Telescope $366 / $436 with Flattener. The ASI533MC Pro is ZWO’s latest OSC camera, and it’s equipped with a 9MP Sony IMX533 CMOS sensor. Seems expensive. eBay item number: 284284336129. 67 / 5 ) $ 770. 50 (ex. Calculate the resolution in arc seconds per pixel of a CCD with a particular telescope. This product is discontinued, for the new 5V EAF please click here. The important performance updates come in the type of ED element combination and the type of focuser the AT102EDL is built around. Inverted monochrome Annotated Large size Full size User. This model fits the Astro Tech 60ED perfectly. It's a 102mm f/7 doublet refractor made with fk61 ED glass. This will be for visual use; no photography planned at this time. Overall the AT80ED will be a great bargain even with KF61 ED glass. Most Read Articles • Contact UsContact Us • Moon PhaseOk, so today I received my brand new Sky Rover 60ED purchased directly from the Aliexpress store. 5″ long with the dewshield retracted and 12. Weighing 19 pounds with tube rings and finder attached, this triplet is a 127mm, f/7. → Astrophotography and Sketching. Astro-Tech AT60ED 60mm or Apertura 60mm FPL-53 Doublet APO Refractor - posted in Refractors : I am looking for a terrestrial scope that can also be used for a grab-and-go scope. JPG . 5 and F6 versions. Astro-Tech Product #: AT60GS . All of the telescopes in the chart above fall under the listed payload capacity of the mount. Cle. 98 (well, 0. 95. Donation is not required by any means, so please enjoy your stay. Set it up once and it will stay in focus forever! Altair GPCAM Guide Camera with an extremely sensitive GPCAM AR0130 Mono sensor connects directly to the MG32 Mini Guider. The aluminum-framed case has three locking latches. Includes the following; 6260 mini 60Ed, 7060 tube rings, 7857 helical focuser, 7604 extention tube, 7364 adapter,7920 adapter, 7317 eyepiece holder and 7885 . For Sale. Altair 60ED, MG32 Guider and EQ3 Pro Synscan mount COMBO £968. 00. 00. There's a batch of Apache sale coupons in the latest HF e-blast if anybody's interested. 00. barx1963. Spencer-3d. 25” non-marring compression ring accessory holders• Vixen dovetail plate. Here are some additional photos captured during yesterday's annular eclipse from Roswell, NM using an Astro Tech 60ED f6 refractor, 1. ) and is 125mm long. It's all a compromise between lightweight portability and light gathering ability. The back focus is 55mm from the shoulder of the reducer to the. 25" · Optolong Red 1. • durable nylon soft carry case. I have taken multiple photos of the moon, m3 and m51 and although my photos may lack technical merit, it has. Page 35 of 37 - AT60ED: Something Small From Our Sponsors - posted in Refractors : Pete mentioned they are expecting stock this month. My two larger, heavier, and more expensive 2" wide-field eyepieces haven't seen much use since I acquired the 28mm UWA over a year ago. The distance needed is 54. Weighing in at just 3. 1 F/7 ED REFRACTOR from our friends at Astronmic this will feel in the gap between my 120mm orion st f/5 and my 127 Orion mak as far as a grab and go scope. Astro-Tech AT60ED 60mm f/6 FPL-53 ED Doublet $369. Ready to go on Celestron AVX mount with ZWO ASIAir Pro and ASI294 color camera. Cloudy Nights. 67 = 2 / 3, 2 = 4 / 2). This camera sensor is quite different from the one in the ASI294. The handle will help making set up much easier as you have a solid part to grab onto and not just the tube. This Astrozap focusing cap with built-in Bahtinov focusing mask will fit most 80mm aperture fast focal ratio ED refractors, such as the Astro-Tech AT80EDT ED triplet apo, or any scope with an optical tube or lens shade measuring between approximately 101mm (4") and 110mm (4. 17 (ex. Telescope Express TS Photoline 60mm f/6 is the same scope as the AT60ED, but a different color. It not only has great reviews, has FPL-53ED glass, and a clear price advantage. Astro-Tech 60ED vs. The Ultimate Kit for the Apertura 60 mm Doublet RefractorIncludes a Full-Frame Field Flattener and 32 mm Guidescope. 5 to f/7 range that use a 2" focuser. 25" (260mm) wide, and 11. Astro-Tech AT80EDT f/6 triplet. Most Read Articles • Contact UsContact Us • Moon PhaseThe Astro-Tech AT80EDT is a great triplet apochromatic refractor. Cost over $1100 on Hutech's site. Re: AT70ED. 6 lbs: 8. Loc: Georgia. 67 = 2 / 3, 2 = 4 / 2). VAT) Sky-Watcher Esprit 100 ED PRO OTA £1,799. I am selling my Astro-Tech 60ed + . AstroTech AT60ED vs William Optics ZS61II - posted in Refractors : Just judging from the descriptions, these two scopes appear to be very close to the same thing. Astro-Tech AT102ED Imaging Cameras ZWO ASI294MM Pro Mounts Sky-Watcher EQ6-R Pro Filters Optolong Blue 1. 83 (ex. 8 reducer for ED60. 9. . 1" F/7 ED REFRACTOR - posted in Refractors : Well just ordered me a ASTRO-TECH AT80ED 3. That means imaging with the AT80EDT requires (6 / 6. Nirvanaepic • 22 days ago. The Astro-Tech AT60ED APO Refractor that I recently purchased. It is compact, well made with a rotating two speed Crayford focuser, a sliding dewshield and nice overall finish. 0mm) = 20. Calculate the resolution in arc seconds per pixel of a CCD with a particular telescope. There are three set-screws which secure this in a recessed track, plus a thumb-screw for locking it in position. 8x reducer/flattener, which are in stock now? I was dead set on the AT60ED for the incredible value but am getting antsy waiting. Page 1 of 2 - AstroTech ED80 vs Orion ED 80 for AP - posted in Refractors : Ok these are the scopes in my price range. This is one of the many variants of the TS, Altair, AstroTech compact refractors available on the market, although a tad faster at F5. Find the position of dust or reflections in your optics. Posts: 137; Joined: 04 Aug 2020; Loc: New Hampshire, NH; Posted 18 April 2021 - 08:31 PM. 5mm) > Filter Holder (17. Someone has had SharpStar painted on the side. And I thought As. com and they have no idea when they will be. Resolution Formula: ( Pixel Size / Telescope Focal Length ) X 206. 00 Not FPL-53. → Equipment Discussions. My Astro-Tech AT80 arrived on Wednesday, along with the Astro-Tech 2-inch Dielectric diagonal. No nicks or marks on any part of the telescope. Page 1 of 5 - Astro Tech 80EDL or 80EDT? - posted in Refractors : Was wondering if anyone has experience between these two scopes. ZWO new Astro Cameras, new accessories: Teleskop-Service is the partner of ZWO in Europe. Astro-Tech . ) They also have reviewed the higher spec Growler 40 some time ago. The Sharpstar 60ED is a versatile telescope that is perfect for viewing celestial objects such as the moon, planets, and stars. 34mm but you also have a t-ring in there too. This uses the FB shoe and has a machined adapter that attaches it to the top of a 1" wide telescope mounting ring. A super portable refractor telescope with FCD100 ED glass, suitable for astrophotography or visual use, day or night-time. Astro-Tech AT60ED Imaging Cameras ZWO ASI533MC Pro Mounts iOptron CEM70EC Filters Antlia ALP-T Dual Band 5nm 2" Accessories Astro-Tech . Altair Astro Limited is a UK Company Currently, I want a frustration free experience before taking up bigger challenge. 265. 5mm flange to sensor spacing). Astro-Tech 60ED Unboxed Equipment Discussions. For the Astro-Tech Field Flattener the optimal spacing from field flattener to film plane: 57mm +/- 4mm and Canon is supposed to be 55. Most Read Articles • Contact UsContact Us • Moon PhaseThe two silver allen bolts in the center of your photo. . Fun to view with. Is there an Astro Tech dealer in Australia or do you purchase direct from the USA? I would like a AT65EQD. Astro Tech, Feather Touch, Please be aware that not all modules from the brands above are supported. The SharpStar 60ED is a Doublet O'Hara ED FPL53 unit. . I have a TV 3-6 zoom so. The user manual says that it provides a library of LabVIEW wrapper around the OmniDriver . Note that the Orion is an. Everything is in good condition, no major issues. 9 specification likely results from a lens cell with a slightly larger entrance pupil). Not wise. . 00. Astro-Tech recently re-released the 65EDQ and was available for immediate delivery. Our shop offers you comfortable online shopping, fast delivery times. 130 mm. Resolution Formula: ( Pixel Size / Telescope Focal Length ) X 206. For Sale. I'd expect them to be similar. Please stay tuned. Pending edit 1; Mounts 621 ; Filters 2238 ; Accessories 1413 ; Software 386 ; Contributors 50 ;Page 1 of 2 - PF vs. 60mm Astro-Tech ED - posted in Refractors : Sears 60mm x 700mm Discoverer (Towa) achromat, circa 1968, vs. Astro-Tech 60ED. You are better off with a short refractor like a Astro-Tech 60ED + 0. 11/10/2023 04:51AM. When Thomas passed away, Astronomics, continued in their support of his family. The optical tube measures 9. 5 to f/7 or so. SWAS70ED-OTA, plus Visual Bundle consisting of 17mm Eyepiece, Star Diagonal, RDF, Bracket / Stalk. 8x flattener. Guidescope Suitability Calculator. Does Not Apply. Not so good for planets. Speed 75m/s Extruder 215C Bed 60C Retraction 0. - posted in Experienced Deep Sky Imaging: Here is my second test of new x0. I have an Astro tech 60ED scope and recently purchased an ATR8 0. • dual-speed 2" Rack and Pinion focuser with built in rotator. It functions as a handle (This is fairly obvious from the name. Hello guys. The Astro-Tech ATRF60 0. They are pretty much optical twins with no. 95. Nor do it see it in my faster Dobs with a. Posted 23 May 2019 - 11:05 AM. The AT80ED is bringing ED optics to you at a fantastic price. in stock Check stock level or request price match [value] £ 99. Cloudy Nights. Star testing is so-so, by my estimate, about 1/4 wave SA under corrected, a little better than that if I use a prism diagonal. The AT70ED is a brand new addition to the Astro-Tech line up, whereas the 60ED and 72EDII have been out for a. Cheers! Bob F. 00 £632. This Astro-Tech ED refractor has:• 72mm f/6 fully multicoated FPL-53 and Lanthanum doublet refractor optics• dual-speed 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. 90. Soyuz. Celestron Astro Fi 6" SCT WiFi Telescope £799. If you wanted this scope but with blue trim, congratulations. → Beginning Deep Sky Imaging. Finally, I have beautiful Rick. 25 diagonal, and a Manfroto camera tripod with pistol grip for easy aiming. The distance needed is 54. Zenithstar 61 II vs. Astromart Customer Service. Happy 2023 to everyone! Ever wanted to take a telescope on vacation with you… but you’re flying there and not driving? You need an instrument considerably sm. 2 oz with the rings and dovetail, 5 lbs 4 oz without rings and dovetail. Both have FPL-53 glass. (TS Photoline 60mm/60ED) which would produce a short and fast 260mm f/4. VAT) Altair 70 EDQ-R F5 Quad APO Astrograph. 5mm or 7mm DeLite for Astro-Tech AT60ED? - posted in Eyepieces: Im primarily a binocular observer (Canon IS 10x42 and 15x50). We have found them to be too long and they have caused damage to the finish of the finderscope drawtube. 7. This evening a new scope arrived, an Astro Tech AT102ED. M51 and companion - at least as bright as my 10" dob. Inside the cap is a wheel that can be rotated to either line up the Bahtinov. The AT80EDT is f/6, the ZS81 is f/6. Orion 2” dielectric diagonal. Incorporates Ohara FPL-53 glass optics for enhanced contrast, color correction, and sharpness. Quadruplet Apochromat.