Page 4 of 23 - WO Fluorostar 91 - new scope - posted in Refractors : Seems like there is a pretty large shipping fee to. The three-element optical design features a 91mm aperture using FPL-53 glass. Orange Bird Wildlife - RED Komodo 6K / WO Redcat 250mm F4. T-FLT-91. William Optics FLT 91 Fluorostar 91mm f/5. ln. William Optics Fluorostar 132 - Space Grey. Filter: Antlia 36mm OIII 3nm Narrowband Filter -. Adjust Distance for DSLR and Mirrorless Camera is 5. William Optics Fluorostar 91 Triplet APO Refractor Telescope with 3. I've been considering a WO FL 91 for awhile to use only in visual observing. doc 3Version 1. 67% Basic astrometry details. add to list Tags BEE-LINK SER5 Pro wall mount and USB Drive Carrie. That is just about the limit of the sky, guiding and diffraction limit for a 91mm aperture. FLT-91 / Flat 68iii elongated stars? - posted in Experienced Deep Sky Imaging: First light on my W-O Fluorostar 91 / Flat 68iii, and could use some advice. 0 TELESCOPE. Details. 900. Wish List Compare 【Refurbished】Zenithstar 73 III APO-Red. 9. I have it, and the optics are great, but the mechanics has sag and tilt. $6,049. Next session will see me adding a total of 2mm. Lo scorso anno avevo presentato sulle pagine di Binomania due rifrattori WIlliam Optics da 61mm e 81 mm della serie Zenithstar. Add to Cart ₹ 23700 + 18% GST FLAT6AIII Special Edition. 3" R&P Focuser. Im having trouble finding honest reviews on the Fluorostar 93. I decided to upgrade to a WO Fluorostar and EQ6-R and the results are super good. The FRA is also a natural f/5. 9)[対物レンズ] 含むFPL53 3枚玉アポクロマート[Strehl Ratio]0. Wish List Compare. Saddle handle bar: Newly designed. Optional. cþl 22mm Weight : 9. These corrective optics work best at a specific distance away from their glass elements, most commonly 55mm. If your sensor is say at 48mm or at 67mm away, you may still see curvature, or still have coma affecting your images. In stock. 3" Rack & Pinion Focuser - Specify Color. 00. William Optics Fluorostar 91 / FLT91 Imaging Cameras ZWO ASI533MC Pro Mounts ZWO AM5 Filters Antlia ALP-T Dual Band 5nm 2" Accessories William Optics Flat68 III · ZWO ASIAIR Plus Software Pleiades Astrophoto PixInsight Guiding Telescopes Or Lenses ZWO 30mm Mini Guider Scope Guiding Cameras ZWO ASI120MMThe Soul Nebula is a large emission nebula located in the constellation Cassiopeia, about 7,000 light-years from Earth. 00. If you have any questions about my experience with the William Optics FLT 91. Not that this was with a 2. 72) Filter: Chroma 36mm SII 3nm Telescope Filter - Unmounted; Filter: Chroma 36mm HA 3nm Telescope Filter - Unmounted;The FLT91 Fluorostar lens is designed to be compatible with various camera mounts, including Canon EF and RF, Nikon F and Z, Sony E, Pentax K, Micro 4/3, and Fuji X T-Mounts. +. New for 2021 – The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence. Broad band images were taken from a Bortle 3 site in Sand Point Michigan while the Ha was shot from my backyard (Bortle 7). 【Refurbished】Fluorostar 91 APO-Red . 5) Reducer/Flattener: William Optics FLAT7A (624mm at F/5. Tags WIlliam Optics Fluorostar 91 ZWO EAF Mount. Has anyone ever put a ZWO EAF on a William Optics Fluorostar 91?William Optics Fluorostar 91 / FLT91 Imaging Cameras ZWO ASI2600MC Pro Mounts Sky-Watcher EQ6-R Pro Acquisition details Dates: Nov. . Sort By: Quick view Compare Add to Cart. The Esprit seems to be bullet proof (almost) but the Fluorostar has had some reports of poor focuser construction. Scribd is the world's largest social reading and publishing site. Fluorostar 91 Mini PC / UPB2 Mount . T-FLT-91. William Optics Fluorostar 91 APO - Red. Qty. Using FPL-53 glass this telescope provides excellent aberration correction. For the guide scope, I don't think this is as critical a choice as the main scope, so I expect something like a WO 50mm or ZWO 30mm would be adequate here. Review. 25" · Antlia Green 1. New Fluorostar 132 (Innovative Bahtinov Mask Cover (Patented) included) 1 Review . William Optics Fluorostar 91 The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a mid. New-36. I just purchased a William-Optics Fluorostar 91 telescope and Flat 68 iii field flattener, and have a question about connecting a ZWO ASI 533 MC Pro camera. The three-element optical design features a 91 mm aperture using FPL53 glass. William Optics Fluorostar 91 APO - Gold. The deep-sky imaging performance of that little APO is what. FLAT6AIII special edition for Fluorostar 91. 8x Flattener/Reducer APO · ZWO ASIAIR Plus SoftwareWilliam Optics Fluorostar 91 / FLT91 Guiding Cameras ZWO ASI174MM Mini Acquisition details Dates: Feb. Free shipping. Like. 00. 9 APO Refractor in Red with 32mm UniGuide and P-FLAT6AIII. TALK TO AN EXPERT : 919833974700. 540mm. Originator 100040680_sandra__bartels. Swap to the smaller Allen key and with a torch find the two screws at 45 degrees so just rotate the focus adjuster to see them. The William Optics FLT 91 is the perfect apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. I have since added another 1. There's an initial grub screw to remove which will them expose the screws holding the gauge to the shaft. # 10/7/2021. 8x reducer (6Aiii), you must be 62. 9) Flattener/Reducer: FLAT6AIII special edition for Fluorostar 91 (432 mm at f/4. View full description. Focal Length. William Optics Fluorostar 91 / FLT91 : Telescope or lens: 105: 949: William Optics Fluorostar 98 / FLT98 : Telescope or lens: 12: 87: William Optics Gran Turismo 102 (f/7. I. Basic Information: Telescope: William Optics FLT 91 with FLAT 6AIII reducer. Focal Length: 540 mm. 99. The three. The three-element optical design features a 91mm aperture using FPL-53 glass. “続いて> FLT-91鏡筒とセットでおすすめなのがフラットナーレデューサー”FLAT6AIII”. Now Only $998. 25 inch RotoLock) All new, a unique, RotoLock high-quality fully multi coated WO 50mm f/4 Guiding scope that fits. Page 1 of 2 - My Fluorostar 91 has arrived - posted in Refractors : My Fluorostar 91 (FLT 91) just arrived. Wish List Compare. Aperture. We would like to show you a description here but the site won’t allow us. Guidescope an option. ) So indeed, FRA600 performs noticeably better with the reducer. The STM coatings and superb quality provide excellent optical performance and unmatched value. The FLT 91 employs FPL-53 glass and has an optical design consisting of three elements. William Optics Fluorostar 91 / FLT91 Imaging Cameras ZWO ASI2600MM Pro Mounts Sky-Watcher HEQ5 PRO Filters Chroma Blue · Chroma Green · Chroma H-alpha 3nm Bandpass · Chroma OIII 3nm Bandpass · Chroma Red Accessories Pegasus Astro Powerbox Micro · William Optics Flat6A III · ZWO EAF · ZWO EFW 7 x 36mm SoftwareThe Fluorostar 110 is designed to work with both 1 1/4 inch and 2 inch diameter eyepieces in various focal lengths, for both daytime and nighttime viewing. High-Quality Refractor Telescopes, Binoculars, Eyepieces, Diagonals and other Optical Accessories. 25″ / 31mm Software Adobe Lightroom Classic · Pleiades Astrophoto PixInsight Guiding Telescopes. The three-element optical design features a 91mm aperture using FPL-53 glass. Most relevant Top fan. Wish List Compare. 72X (TKA36580L) · William Optics Flat6A III. add to list. The eccentricity plot has a weird looking, but it's rather uniform, from 0. ZWO AM5 mount. 00. 00. You're reviewing: FLAT6AIII special edition for Fluorostar 91. Brands / Companies 910 ; Cameras 3302 ; Sensors 465 ; Telescopes & lenses 3721 . As low as $1,998. Details. P-FLAT6AIII-M92. The William Optics Fluorostar 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. 00. SKU. A soft carry case comes standard with the William Optics Fluorostar 91. I would really appreciate any comments that my help with making choice from those that have had some experience with either scope or either. 8 These are premium instruments. Unit price. 25 , , , , , Download: free Website: Thingiverse. 00-425212-01. 9 Triplet Apo Refractor. William Optics Fluorostar 91 0. 8 Guiding Cameras ZWO ASI290MM Mini Acquisition details Dates: April 14, 2021Page 15 of 23 - WO Fluorostar 91 - new scope - posted in Refractors : FLT91 > Flat 6AIII @ 5. 77 degrees (see scope mounted, Version B). $99. Filter: Chroma 36mm OIII 3nm Telescope Filter - Unmounted. The FLT 91 is the perfect apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. Ken Bates. Add to Cart. 1. Adapters. Now Only $998. 3" Rack & Pinion Focuser - Space Grey Version. add to list. Fluorostar series. I have a Redcat 51, a Zenithstar 73, and a Fluorostar 91. 575kg (OTA with William Optics Fluorostar 91 Triplet APO Refractor Telescope with 3. $1,933. 00. Most of the work went into de-emphasizing the stars to make the nebulosity stand out. Diameter. Shop Home / Accessories / Boltwood Cloud Sensor III Brand: Diffraction Limited Accessories Boltwood Cloud Sensor III. Posted 07 March 2022 - 08:46 PM. Focuser. New listings: American Range stove oven A32610 A32616 Gas Valve On Off Knob FLT Down $25, William Optics Fluorostar FLT 91 Triplet APO Refractor Telescope $1 775An astrophotograph by Trevor Bray on AstroBinFor astrophotography, the large image circle provides illumination, even for full-frame cameras. 00. 5mm spacer, but got elongated stars in the four corners. The three-element optical design features a 91mm aperture using FPL-53 glass. 510mm. Wolf–Rayet stars are evolved, massive stars that have completely lost their outer hydrogen and are. QC issues described here are something that one would not expect from such established producer. Be the first to review this product . add to list Tags Pegasus Astro Powerbox Advance. The STM-coatings and superb quality provide excellent optical performance and unmatched value. Fluorostar 91 Trailer. RotoLock Adapters; Camera / T-Mount Adapters; Mounting. Write Your Own Review. William Optics Fluorostar 91 / FLT91 / New scope and flattener/reducer; New scope and flattener/reducer. Wish List Compare. This flattener contains a 63 mm opening on one end that threads into the telescope, and an M48x0. The STM-coatings and superb quality provide excellent optical performance and unmatched value. The STM-coatings and superb quality provideEasyQuest. The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. Retracted Length. Tilt in my Fluorostar 91 and image train - please help with process here - posted in Beginning Deep Sky Imaging: Hi All Thanks in advance for help/advice you can provide. Add to Cart. 510mm. 0 Items - $0. If I had to do it over again, I would completely skip the Zenithstar. Those look so nice. 9. The William Optics Fluorostar 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. Whereas the WO 91 is a natural f/5. Fluorostar 91. Fluorostar 120. William Optics Fluorostar 91 / FLT91 Imaging Cameras ZWO ASI2600MM Pro Mounts ZWO AM5 Filters Optolong H-Alpha 3nm 2" · Optolong OIII 3nm 2" · Optolong SII 3nm 2" Accessories William Optics Flat68 III · ZWO ASIAIR Plus · ZWO EAF · ZWO EFW 5 x 2" Software Pleiades Astrophoto PixInsightSky-Watcher Esprit 100ED · William Optics Fluorostar 91 / FLT91 Imaging Cameras ZWO ASI2600MM Pro · ZWO ASI294MC Mounts Sky-Watcher EQ6-R Pro Filters Astronomik CLS-CCD 36mm · Astronomik Deep-Sky Blue 36mm · Astronomik Deep-Sky Green 36mm · Astronomik Deep-Sky Red 36mm · Astronomik H-alpha CCD 6nm 36mm. Extension Tube Length. The STM coatings and superb quality provide excellent optical performance and unmatched value. 00. The new William Optics Fluorostar FLT 91 is a three element air-spaced apochromatic refractor with a focal ratio of f/5. All reactions: 155. 5mm to sensor) Im guessing that everyones spacing may be slightly different and even WO basically says the 5. ln addition, with STM-coatings enabling superb optical performance, the FLT 91 provides excellent. The 120mm air-spaced ED APO Triplet optics, made of FPL-53 ED and Schott BK-7 glass, coupled with multi-layers of a high transmission coating, yield sharp, high contrast views with no extraneous color. , , , , , Download: free Website: Thingiverse. The confused or confusing information that WO puts out re 68III backfocus is unhelpful as has been noted. William Optics Fluorostar 91 / FLT91 Imaging Cameras ZWO ASI533MM Pro Mounts iOptron CEM60 Filters Antlia Blue 1. I recently acquired the William Optics Fluorostar 91 as both a visual and imaging telescope. The FLT 91 is an Apochromatic refractor with a focal length of 540 mm and an aperture of f/5. To see how to install the Flat6Aiii including the correct back focus go to the following link:two flatteners/focal reducers is like having two telescopes with different focal lengths. . The FLT 91 employs FPL-53 glass and has an optical design consisting of three elements. OK, I'm tempted by the FLT 91 I already have a WO 6A III 0. $2,494. For a guide camera I'm thinking an ASI120MM or a ASI220MM -- Is there any advantage to the more expensive. New for 2021 - William Optics Fluorostar / FLT 91 An Apochromatic triplet refractor for visual astronomers and astrophotographers who want very high performance from a midsize telescope. Help with focusing on a new setup - posted in Experienced Deep Sky Imaging: Hello! I just received a new William Optics telescope and tried it for the first time. ln. The W-O web site for the Flat 68 iii shows the back focus for the FLT91 as 75 mm, but also indicates the adjustment distance for a DSLR or mirrorless camera as 5 mm. 8 Reducer - DIY 3D printed guide cam with IMX290 and ZWO 30F4 Acquisition Details: - 100 x 120s + 230 x 60s - 0 gain. Oggetto di questa recensione. 5") 1,998: William Optics Gran Turismo 71 APO Refractor: Triplet Refractor: 71 mm (2. Page 5 of 23 - WO Fluorostar 91 - new scope - posted in Refractors : I have the Flat6AIII on my GT71, M63 focuser thread, and the 68III on my FLT 132, M92 focuser thread. → Refractors. 5477779_1 GE OEC Fluorostar 91 Segurança contra radiação. If your camera chip is too close or too far away, then the elements will not actually perform their intended corrections. CLOSED: Thanksgiving, Christmas Day, New Year's Day. Messier 48 can be found 14 degrees to the southeast of Procyon, the. Mounting Rings;Business, Economics, and Finance. Astronomers desirous of superb visual and photographic intermediate sized refractor performance will much appreciate the William Optics 91 mm f/5. I do however, use their instruments for astrophotography and so I was surprised. Nickname. 00. 25" WA 1. Its a nice scope, but its too large to carry in my truck. 02. With a 3-element triplet design and FPL-53 glass, this William. 00 My account / Register. Hey, Brian, FWIW, I'd avoid the FLT 91. FLAT6AIII special edition for Fluorostar 91. The FRA is also a natural f/5. Sky-Watcher Explorer 130PDS 12. 72) Filter: Chroma 36mm HA 3nm Telescope Filter - Unmounted. This very elegant 2" reducer/field flattener has been designed to optimize the flat-f. Triplet Air spaced lens, TMB design, Triplet Air spaced lens, TMB. FLT151 Features a top-quality triplet air-spaced objective using outstanding Ohara FPL-53 type glass which provides superb correction for these refractors. It is the result of a shock wave emanating from a Wolf-Rayet star. T-FLT-91-SG-Refurbished. Add to Wish List. Crypto2. A 300 f/2. Heavy-Duty Focuser with Integrated Camera Rotator, Tube Rings, Soft Case and Accessories. Add to Cart. Add to Cart. 72. The STM coatings and superb quality provide excellent optical performance and unmatched value. Our Price: $1,998. 1 Escopo Este manual contém informações sobre a operação do sistema, os componentes, as chaves de controle, os interruptores e riscos dos dispositivos Fluorostar Compact e Series GE OEC. I do however, use their instruments for astrophotography and so I was surprised by the general feedback regarding their newly released. 3" Rack & Pinion Focuser. In stock. I have somewhat narrowed it down between an Esprit 100 or the William Optics Fluorostar 91. Filters: Chroma SHO 3nm - 36mm. Fluorostar 91. I can only say that Esprit owners seem well satisfied and and the same is true of Willams Optics scope owners. C. Vendor William Optics Regular price $1,998 Sale price save $-1,998 Unit price / per . EAF Manual EAF Manual EN V1. The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. Retracted Length. Looking at the FLT91, assuming it comes in at $2k, adding a flattener and flattener/reducer brings it up to $3300 (Im assuming it will need the larger flatteners). The WO being only a triplet would not be flat across the entire field. Email: [email protected] Optics Fluorostar 91 / FLT91 Imaging Cameras ZWO ASI294MC Pro Mounts iOptron CEM70G Acquisition details Dates: Jan. Fluorostar 91 BUY NOW New for 2021 - The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. 9 Triplet Apo Refractor with Carry Case - Space Gr. • Can be used in both autofocus and manual modes. Apochromatic Triplet Prime Lens. William Optics RedCat 51 (Unboxing) 0:16. 3" ラックアンドピニオン. Add to Cart. Had to fiddle with the installation as I ended up putting the mount screws into one of the focusing tighteners and so it wasnt able to focus, but once Id figured that out and used the different mounting holes on the bottom of the. 6 and can be reduced with a reducer to f/3. As low as $730. William Optics RedCat 51 (Unboxing) 0:16. Utilizing FPL-53 synthetic fluorite glass with STM coatings, this telescope provides excellent aberration correction and amazing optical performance. 4mm spacing is more or less a. Backfocus is adjustable up to 15 mm, and, once set, is held in place by a locking ring. With a 3-element triplet design and FPL-53 glass, this William Optics 91 mm f/5. If they were just sourcing and retailing scopes like some other brands, I'd expect to be able to easily find equivalents to, say, the RedCat 71 or the Fluorostar 91. 56% Hot. 00. Fluorostar 91 -ZWO EAF. 6 and can be reduced with a reducer to f/3. The back focus started at 60mm which is the required distance when using the Williams Optics FLT 91 with the FLAT6AIII, I have a filter in the image train so I added a 0. SKU. William Optics Fluorostar 91mm. More Information. skysurvey, on 15 Nov 2020 - 06:16 AM, said: No, the WO 91 Fluorostar isn't any cheap but I have no idea why, IMO we are talking about a 2515€ telescope and about a 1382€ telescope that are the same, don't let you that 1mm of difference confuse you. 3″ R&P Focuser Color Red Space greyWilliam Optics Fluorostar 91 / FLT91 Imaging Cameras ZWO ASI2600MC Pro Mounts ZWO AM5 Filters Optolong L-Ultimate 2" Accessories William Optics Flat68 III · ZWO ASIAIR Plus · ZWO EAF Software Pleiades Astrophoto PixInsight Acquisition details Dates: Dec. 9 aperture, this Fluorostar model strikes a balance between a wide field of view and detailed imagery, ideal for casual, serious stargazers and wide field imagers. 8 These are premium instruments primarily aimed at astrophotographers, but they can also be used for visual observations. Some of William Optics’ most well-known telescopes include: William Optics RedCat 51; William Optics RedCat 71Observing mode: 121mm Aperture size: 65mm Net weight: 2Kg Focal length: 416mm Gross weight: 2. 00. Both about the same price. 2y. 4mm. Both the Fluorostar 91 and Redcat 71 are dropping in the December/January time frame. 00 Original price. The hottest star in the cluster has the stellar classification A2 and a visual magnitude of 8. 8 works well on light mounts (as well as big ones). $1,568. I'm also including the Flat 6AIII 0. Add to Cart-23. Using the appropriate T-Mount and T-ring, users can create a functional imaging setup with the FLT91. 【Refurbished】Fluorostar 91 APO-Space Grey. 00. Qty. STAR 91 Ml 21 SPECIFICATION M92 M92 M83 Focal Length : 540mm Diameter : 91 mm Aperture : f/ 5. The back focus started at 60mm which is the required distance when using the Williams Optics FLT 91 with the FLAT6AIII, I have a filter in the image train so I added a 0. As low as $1,998. Its a nice scope, but its too large to carry in my truck. Now Only $1,398. WO Fluorostar 91 - new scope. 9 APO Triplet Refractor Telescope FPL-53 William Optics Fluorostar 91 FLT91 f/5. Cant imagine the 6AIII on the FLT132 with a M92-M63 adapter. - -10C cooled - Shot on April 26 and 27 night - 32 flats, darks, bias for each night Processing Details (PixInsight only):. Really enjoying the new setup. Component What I use; Optics: William Optics Fluorostar 91 w/reducer: Filter Wheel: ZWO 7-position automated filter wheel (50mm/2″) Filters: Astronomik Deep Sky Red, Green, Blue, plus MaxFR Ha, and L1 luminance (Astronomik Oxygen III and Sulfur II filters are on order) Stellarvue and Feather Touch, here I come. Wish List Compare. It offers remarkable image quality, surpassing most telescopes of its kind in its ability to eliminate optical defects. Fluorostar 91 APO. Fluorostar series. The STM coatings and superb quality provide excellent optical performance and unmatched value. William Optics Fluorostar 91 / FLT91 / Star finder scope; Star finder scope. Look no further than Bintel, where we endeavor to provide high quality service and after-sales support second-to-none! We stock a wide range of great telescopes and have been supplying amateur astronomers in Australia for over 30 years. 61 pixel). Back Ordered. The FRA500 is slightly lighter and slightly smaller in length. SKU. Fluorostar 91 APO Fluorostar 91 APO Fluorostar 91 APO Fluorostar 91 APO Fluorostar 91 APO Christmas Tree Nebula by By Nihar Nair Christmas Tree Nebula by By Nihar Nair. FLT-91 / Flat 68iii elongated stars? - posted in Experienced Deep Sky Imaging: First light on my W-O Fluorostar 91 / Flat 68iii, and could use some advice. The William Optics FLT 91 is the perfect apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. As low as $1,568. Write Your Own Review. Not super happy with the debugging. Title Spare Part List Fluorostar 2nd Edition lower SN 10000. 25" · Antlia Luminance 1. 8x reducer is almost identical FOV as the Zenithstar was, but gathers more light and faster, and the Zenithstar was not as good as the Redcat anyway. Technical Specifications. William Optics FLT 156 - posted in Refractors : For those who may be interested, William Optics has just listed its Fluorostar 156 f/7. $284. Unfortunately, I was not able to get the focus right. Add to Cart. I really like what I’ve read up on William Optics and would like to purchase one. Great in aiding in quick diagnoses when time is of the essence. Put the correct sized flex coupler on the exposed shaft and tighten the grub screws down through the hole created by the grub screw removed earlier. I am new to astronomy. So far, the stars are looking better and better as I back it out more. William Optics. 00. → Equipment Discussions. And attached is a FWHM-Eccentricity analysis of the luminance data. 00. How to install the ZWO EAF on the William Optics Fluorostar 91. Tags Bahtinov Mask for William Optics UniGuide 32mm. You may remember my review of the William Optics Zenithstar 61 APO, which also used this glass. The Zone at 91-3, Victoria, British Columbia. The 68III is at least twice as big and twice as heavy as the 6AIII. Its always a shame to take off the visual back on these. 5 Items. 9. The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. 00. I am using the UBP2 optional brackets to hold the miniPC and mount to the bracket. Be the first to review this product . Add to Cart. The STM-coatings and superb quality provide excellent optical performance and unmatched value. WANT! 2y. 5599179_3 GE OEC Fluorostar Compact/Series 17. Using the appropriate T-Mount and T-ring, users can create a functional imaging setup with the FLT91. 00-425243-01. The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. Altair Wave Series 115 F7 ED Triplet 1 6. Each subs are fives minutes long and each panel is eights hours of exposure so. The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. 06 pixels is 2. Product Details. 00. FLT 91 with the Flat 6AIII x0. 75") 933: William Optics Gran Turismo 71 APO Refractor with Flattener: Triplet Refractor: 71 mm (2.