Telescope specifications for imaging
Specifications for 119 telescopes and astrographs from Sky-Watcher, Celestron, William Optics, Askar, Sharpstar: aperture, focal length, focal ratio and, where the maker publishes them, image circle, back focus and the official reducer or flattener. Focal length and pixel size together set the image scale; focal length and sensor size set the field of view.
The family pages group related tubes and add a field-of-view table for common sensors. Back focus figures mean different things on different products (from the flattener thread, from a rotator, or a recommended spacing), so check the linked page before ordering adapters.
Telescope families and comparisons
-
Askar APO, F and N series
Askar APO triplets (700–1421 mm), self-flattened F refractors and f/3.6 N Newtonians: reducer focal lengths, a 28 mm image circle, and which sensors fit.
-
Askar SQA, FRA and PHQ
Askar SQA, FRA and PHQ astrographs: how the three lines differ, 0.7x–0.76x reducers with published focal lengths, and back focus measured from different threads.
-
Celestron RASA astrographs
Celestron RASA astrographs at f/2–f/2.2: published image circles vs sensor diagonals, camera body and back focus limits at prime focus, and how filters fit.
-
Celestron SCT and EdgeHD
Celestron classic SCTs vs EdgeHD: the f/6.3 reducer vs 0.7x EdgeHD lenses, the 133.35/146.05 mm back focus, and why the manual's focal lengths differ.
-
Sharpstar astrographs
Sharpstar f/2.8 HNT Newtonians, SCA260 and SCA310 Cassegrains and the Z4 refractor: image circles, obstruction, and which EDPH models are discontinued.
-
Sky-Watcher Esprit triplets
Esprit ED and EDX triplets from 400 to 1050 mm: which flattener came in the box, the 0.77x reducers for the 120 and 150, and the 70EDX's 490 vs 455 mm focal length.
-
Sky-Watcher Evostar ED doublets
Sky-Watcher ED doublets: discontinued Evostar ED vs current EDX, matched reducers, published reduced focal lengths and the 0.92x vs 1.0x flattener conflict.
-
Sky-Watcher imaging Newtonians
Sky-Watcher PDS (f/5) and Quattro (f/4) imaging Newtonians: coma correctors that keep focal length, the Quattro 150P's 518 mm reducer and published secondary sizes.
-
Sky-Watcher Maksutovs and Dobsonians
Skymax Maksutovs (1300–2700 mm) and Classic/Flextube Dobsonians: exit pupil and magnification limits, planet image scale, and the Skymax 127 spec conflict.
-
Small refractors under 400 mm
Sixteen small refractors from 178 to 408 mm compared on APS-C field, image scale, focal ratio and image circle against APS-C and full-frame diagonals.
-
William Optics Cat refractors
William Optics' Cat Petzval astrographs: the RedCat to Cat WIFD rename, MiniCat, Mighty-Cat and Ultra-Cat, image circles, and the 55 ± 3 mm spacing WO recommends.
-
WO Zenithstar, GT, Pleiades, FluoroStar
William Optics doublets, triplets and Pleiades astrographs: flatteners published only as factors, computed focal lengths, per-scope back focus, FluoroStar 156.
All telescopes
Model names link to the manufacturer's specification page. Select a column heading to sort.
| Model | Design | Aperture (mm) | Focal length (mm) | Focal ratio | Image circle (mm) | Back focus (mm) | Weight (kg) | Official reducer or flattener |
|---|---|---|---|---|---|---|---|---|
| Sky-Watcher Evostar 72ED (discontinued) | ED doublet apochromatic refractor (air-spaced) | 72 | 420 | f/5.8 | not published | not published | not published | 0.85x Reducer/Flattener for EvoStar 72ED: 355 mm, f/4.93 |
| Sky-Watcher Evostar 80ED (discontinued) | ED doublet apochromatic refractor (air-spaced) | 80 | 600 | f/7.5 | not published | not published | not published | Reducer/Corrector (.85x) for Evostar 80: 510 mm, f/6.3 |
| Sky-Watcher Evostar 100ED (discontinued) | ED doublet apochromatic refractor (air-spaced) | 100 | 900 | f/9 | not published | not published | not published | Reducer/Corrector (.85x) for Evostar 100: 765 mm, f/7.56 |
| Sky-Watcher Evostar 120ED (discontinued) | ED doublet apochromatic refractor (air-spaced) | 120 | 900 | f/7.5 | not published | not published | not published | Reducer/Corrector (.85x) for Evostar 120: 765 mm, f/6.3 |
| Sky-Watcher Evostar 150DX (discontinued) | ED doublet apochromatic refractor (air-spaced) | 150 | 1200 | f/8 | not published | not published | not published | 0.77x Reducer/Flattener for EvoStar 150DX: 930 mm, f/6.2 |
| Sky-Watcher Evostar 80EDX | ED doublet apochromatic refractor (one Ohara FPL-53 element) | 80 | 600 | f/7.5 | not published | not published | 4 | 0.85x Focal Reducer/Field Flattener: 510 mm, f/6.375 |
| Sky-Watcher Evostar 100EDX | ED doublet apochromatic refractor (one Ohara FPL-53 element) | 100 | 700 | f/7 | not published | not published | 5.5 | 0.92x Focal Reducer/Field Flattener: 644 mm, f/6.44 |
| Sky-Watcher Evostar 120EDX | ED doublet apochromatic refractor (one Ohara FPL-53 element) | 120 | 900 | f/7.5 | not published | not published | 6.74 | 0.85x Focal Reducer/Field Flattener: 765 mm, f/6.375 |
| Sky-Watcher Evostar 150EDX | ED doublet apochromatic refractor | 150 | 1200 | f/8 | not published | not published | 9.68 | 0.77x Focal Reducer/Field Flattener: 924 mm, f/6.2 |
| Sky-Watcher Evolux 82ED | ED doublet apochromatic refractor (one ED element) | 82 | 530 | f/6.45 | not published | not published | 2.95 | 0.9x Reducer/Corrector for Evolux 82mm: 477 mm, f/5.8 |
| Sky-Watcher Esprit 80ED (discontinued) | ED triplet super-apochromatic refractor (air-spaced, FPL-53) | 80 | 400 | f/5 | not published | not published | not published | Included 2-element field flattener/corrector |
| Sky-Watcher Esprit 100ED (discontinued) | ED triplet super-apochromatic refractor (air-spaced, FPL-53) | 100 | 550 | f/5.5 | not published | not published | not published | Included 2-element field flattener/corrector |
| Sky-Watcher Esprit 120ED (discontinued) | ED triplet super-apochromatic refractor (air-spaced, FPL-53) | 120 | 840 | f/7 | not published | not published | not published | Included 2-element field flattener/corrector; 0.77x Reducer/Flattener for Esprit 120: 647 mm, f/5.4 |
| Sky-Watcher Esprit 150ED (discontinued) | ED triplet super-apochromatic refractor (air-spaced, FPL-53) | 150 | 1050 | f/7 | not published | not published | not published | Included 2-element field flattener/corrector; 0.77x Reducer/Flattener for Esprit 150: 810 mm, f/5.4 |
| Sky-Watcher Esprit 70EDX | ED triplet super-apochromatic refractor (one Hoya FCD100 element) | 70 | 490 | f/7 | not published | not published | 3.2 | Esprit 70EDX / Evostar 100EDX flattener: 451 mm, f/6.4 |
| Sky-Watcher Esprit 80EDX | ED triplet super-apochromatic refractor (one Ohara FPL-53 element) | 80 | 400 | f/5 | not published | not published | 3.97 | Optional matched field flattener (Esprit 80EDX) |
| Sky-Watcher Esprit 100EDX | ED triplet super-apochromatic refractor (one Ohara FPL-53 element) | 100 | 550 | f/5.5 | not published | not published | 7.36 | Esprit 100EDX field flattener |
| Sky-Watcher Esprit 120EDX | ED triplet super-apochromatic refractor (one Ohara FPL-53 element) | 120 | 840 | f/7 | not published | not published | 10.84 | Esprit 120EDX field flattener; 0.77x Reducer/Flattener for Esprit 120: 647 mm, f/5.4 |
| Sky-Watcher Esprit 150EDX | ED triplet super-apochromatic refractor (one Ohara FPL-53 element) | 150 | 1050 | f/7 | not published | not published | 15.2 | Esprit 150EDX field flattener; 0.77x Reducer/Flattener for Esprit 150: 810 mm, f/5.4 |
| Sky-Watcher BK130PDS | Parabolic Newtonian reflector | 130 | 650 | f/5 | not published | not published | 3.66 | F5 Coma Corrector (2") for Newtonian Reflectors: 650 mm, f/5 |
| Sky-Watcher BK150PDS | Parabolic Newtonian reflector | 150 | 750 | f/5 | not published | not published | 6 | F5 Coma Corrector (2") for Newtonian Reflectors: 750 mm, f/5 |
| Sky-Watcher BK200PDS | Parabolic Newtonian reflector | 200 | 1000 | f/5 | not published | not published | 8.75 | F5 Coma Corrector (2") for Newtonian Reflectors: 1000 mm, f/5 |
| Sky-Watcher Quattro 150P | Newtonian astrograph (parabolic primary) | 150 | 600 | f/4 | not published | not published | 5.7 | Included coma corrector/reducer (Quattro 150P): 518 mm, f/3.45 |
| Sky-Watcher Quattro 200 ST (US: Quattro 200P) | Newtonian astrograph (parabolic primary) | 205 | 800 | f/4 | not published | not published | 9.5 | F4 Coma Corrector for Quattro: 800 mm, f/3.9 |
| Sky-Watcher Quattro 250 ST (US: Quattro 250P) | Newtonian astrograph (parabolic primary) | 254 | 1000 | f/4 | not published | not published | 15.1 | F4 Coma Corrector for Quattro: 1000 mm, f/3.9 |
| Sky-Watcher Quattro 300P | Newtonian astrograph (parabolic primary) | 305 | 1200 | f/4 | not published | not published | not published | Quattro Coma Corrector: 1200 mm, f/3.9 |
| Sky-Watcher Skymax 102 | Maksutov-Cassegrain | 102 | 1300 | f/12.7 | not published | not published | not published | none listed on the product page |
| Sky-Watcher Skymax 127 | Maksutov-Cassegrain | 127 | 1540 | f/12.1 | not published | not published | not published | none listed on the product page |
| Sky-Watcher Skymax 150 | Maksutov-Cassegrain | 150 | 1800 | f/12 | not published | not published | not published | none listed on the product page |
| Sky-Watcher Skymax 180 | Maksutov-Cassegrain | 180 | 2700 | f/15 | not published | not published | not published | none listed on the product page |
| Sky-Watcher Classic 150P | Newtonian reflector (parabolic primary) on Dobsonian base | 152 | 1200 | f/7.9 | not published | not published | not published | none listed on the product page |
| Sky-Watcher Classic 200P | Newtonian reflector (parabolic primary) on Dobsonian base | 203 | 1200 | f/5.9 | not published | not published | not published | none listed on the product page |
| Sky-Watcher Classic 250P | Newtonian reflector (parabolic primary) on Dobsonian base | 254 | 1200 | f/4.7 | not published | not published | not published | none listed on the product page |
| Sky-Watcher Flextube 300P | Newtonian reflector (parabolic primary) on Dobsonian base | 305 | 1500 | f/4.9 | not published | not published | not published | none listed on the product page |
| Celestron C5 | Schmidt-Cassegrain | 127 | 1250 | f/10 | not published | not published | 2.72 | Reducer/Corrector: 788 mm, f/6.3 |
| Celestron C6 | Schmidt-Cassegrain | 150 | 1500 | f/10 | not published | not published | 4.54 | Reducer/Corrector: 945 mm, f/6.3 |
| Celestron C8 | Schmidt-Cassegrain | 203.2 | 2032 | f/10 | not published | not published | 5.67 | Reducer/Corrector: 1280 mm, f/6.3 |
| Celestron C9.25 | Schmidt-Cassegrain | 235 | 2350 | f/10 | not published | not published | 9.07 | Reducer/Corrector: 1481 mm, f/6.3 |
| Celestron C11 | Schmidt-Cassegrain | 279.4 | 2800 | f/10 | not published | not published | 12.4 | Reducer/Corrector: 1764 mm, f/6.3 |
| Celestron C14 | Schmidt-Cassegrain | 355.5 | 3910 | f/11 | not published | not published | 21 | Reducer/Corrector: 2463 mm, f/7 |
| Celestron EdgeHD 8 | Aplanatic flat-field Schmidt-Cassegrain (EdgeHD) | 203.2 | 2032 | f/10 | 42 | 133.35 | 6.35 | Reducer Lens .7x - EdgeHD 800: 1422 mm, f/7 |
| Celestron EdgeHD 9.25 | Aplanatic flat-field Schmidt-Cassegrain (EdgeHD) | 234.95 | 2350 | f/10 | 42 | 146.05 | 9.53 | Reducer Lens .7x - EdgeHD 925: 1645 mm, f/7 |
| Celestron EdgeHD 11 | Aplanatic flat-field Schmidt-Cassegrain (EdgeHD) | 279.4 | 2800 | f/10 | 42 | 146.05 | 13 | Reducer Lens .7x - EdgeHD 1100: 1960 mm, f/7 |
| Celestron EdgeHD 14 | Aplanatic flat-field Schmidt-Cassegrain (EdgeHD) | 356 | 3910 | f/11 | 42 | 146.05 | 21 | Reducer Lens .7x - EdgeHD 1400: 2737 mm, f/7 |
| Celestron RASA 8 | Rowe-Ackermann Schmidt Astrograph | 203 | 400 | f/2 | 22 | 29 | 7.7 | none listed on the product page |
| Celestron RASA 11 V2 | Rowe-Ackermann Schmidt Astrograph | 279 | 620 | f/2.2 | 43.3 | 72.8 | 19.5 | none listed on the product page |
| Celestron RASA 36 cm V2 (14-inch) | Rowe-Ackermann Schmidt Astrograph | 355.6 | 790 | f/2.2 | 60.1 | 77.5 | 34.02 | none listed on the product page |
| Celestron RASA 6 | Rowe-Ackermann Schmidt Astrograph | 152 | 335 | f/2.2 | 16 | 17.5 | 3.8 | none listed on the product page |
| Celestron StarSense Explorer DX 130AZ | Newtonian reflector (parabolic primary) | 130 | 650 | f/5 | not published | not published | 3.99 | none listed on the product page |
| William Optics Cat 51 WIFD (current RedCat 51) | 4-element Petzval | 51 | 250 | f/4.9 | 48 | 55 | 1.77 | none listed on the product page |
| William Optics RedCat 51 MK2.5 (discontinued) | 4-element Petzval | 51 | 250 | f/4.9 | 43 | not published | 1.3 | none listed on the product page |
| William Optics Cat 61 WIFD (current RedCat 61) | 4-element Petzval | 61 | 300 | f/4.9 | 46 | 55 | 2.47 | none listed on the product page |
| William Optics Cat 71 WIFD | 4-element Petzval | 71 | 350 | f/4.9 | 48 | 55 | 3.22 | none listed on the product page |
| William Optics RedCat 71 (discontinued) | 4-element Petzval | 71 | 348 | f/4.9 | 43 | not published | 2.8 | none listed on the product page |
| William Optics Cat 91 WIFD | 5-element advanced Petzval (2 Super ED, 1 ED, 1 lanthanum, 1 'X-element') | 91 | 448 | f/4.9 | 55 | 55 | 4.72 | none listed on the product page |
| William Optics MiniCat 51 WIFD | 6-element Petzval (2 Super ED) | 51 | 178 | f/3.5 | 43.2 | 55 | 1.67 | none listed on the product page |
| William Optics Ultra-Cat 56 | 5-element advanced Petzval (2 Super ED, 1 ED, 1 lanthanum, 1 'X-element') | 56 | 269 | f/4.8 | 50 | 55 | 2.56 | none listed on the product page |
| William Optics Ultra-Cat 76 | 5-element advanced Petzval (2 Super ED, 1 ED, 1 lanthanum, 1 'X-element') | 76 | 365 | f/4.8 | 50 | 55 | 3.81 | none listed on the product page |
| William Optics Ultra-Cat 108 | 5-element advanced Petzval (2 Super ED, 1 ED, 1 lanthanum, 1 'X-element') | 108 | 518 | f/4.8 | 60 | 55 | 7.96 | none listed on the product page |
| William Optics Ultra-Cat 131 | 5-element advanced Petzval (2 Super ED, 1 ED, 1 lanthanum, 1 'X-element') | 131 | 648 | f/4.9 | 60 | 55 | 11.3 | none listed on the product page |
| William Optics Mighty-Cat 71 (30th Anniversary Limited Edition) | 7-element EVO Petzval (includes 3 Super ED) | 71 | 230 | f/3.2 | 43.2 | 55 | 3.38 | none listed on the product page |
| William Optics Pleiades 68 | 7-element astrograph (3 Super ED) | 68 | 260 | f/3.8 | 48 | not published | 2.98 | none listed on the product page |
| William Optics Pleiades 111 | 7-element astrograph (3 Super ED) | 111 | 528 | f/4.8 | 45 | not published | 7.95 | none listed on the product page |
| William Optics Pleiades 181 | 7-element astrograph (3 Super ED) | 181 | 998 | f/5.5 | 55 | not published | 15 | none listed on the product page |
| William Optics Zenithstar 61 II | Doublet APO | 61 | 360 | f/5.9 | 45 | not published | 2.2 | FLAT 61A: 360 mm, f/5.9; FLAT 61R (0.8x): 288 mm, f/4.7 |
| William Optics Zenithstar 73 III (discontinued) | Doublet APO | 73 | 430 | f/5.9 | 45 | not published | 2.83 | FLAT 73A: 430 mm, f/5.9; FLAT 73R (0.8x Reducer): 344 mm, f/4.7 |
| William Optics Zenithstar 81 WIFD | Doublet APO | 81 | 559 | f/6.9 | 45 | not published | 3.55 | FLAT 6AIII (0.8x Reducer): 447 mm, f/5.5 |
| William Optics Zenithstar 103 | Doublet | 103 | 711 | f/6.9 | not published | not published | 4.36 | FLAT 6AIII (0.8x Reducer): 569 mm, f/5.5 |
| William Optics Gran-Turismo 71 II | Triplet APO | 71 | 419 | f/5.9 | 44 | not published | 2.95 | FLAT GT: 419 mm, f/5.9; FLAT 6AIII (0.8x Reducer): 335 mm, f/4.7 |
| William Optics Gran-Turismo 81 IV | Triplet APO | 81 | 478 | f/5.9 | 45 | not published | 3.9 | FLAT GT: 478 mm, f/5.9; FLAT 6AIII (0.8x Reducer): 382 mm, f/4.7 |
| William Optics Gran-Turismo 81 WIFD | Triplet APO | 81 | 478 | f/5.9 | 45 | not published | 3.58 | FLAT GT (requires adapter): 478 mm, f/5.9; FLAT 6AIII (0.8x Reducer): 382 mm, f/4.7; FLAT 68III (requires adapter): 478 mm, f/5.9 |
| William Optics Gran Turismo 102 | Triplet | 102 | 703 | f/6.9 | not published | not published | 5 | FLAT 68III: 703 mm, f/6.9; FLAT 7A (0.8x Reducer): 562 mm, f/5.5; FLAT 8 (0.72x Reducer): 506 mm, f/5 |
| William Optics Gran-Turismo 153 | Triplet APO | 153 | 1188 | f/7.8 | 43.2 | not published | 13.64 | FLAT 68III: 1188 mm, f/7.8; FLAT 7A (0.8x Reducer): 950 mm, f/6.2; FLAT 8 (0.72x Reducer): 855 mm, f/5.6 |
| William Optics FluoroStar 91 | Triplet APO | 91 | 540 | f/5.9 | 43 | not published | 4.16 | FLAT 68III (requires adapter): 540 mm, f/5.9; FLAT 6AIII (0.8x Reducer, requires adapter): 432 mm, f/4.7; Ultra Flat 91 (0.79x Reducer): 427 mm, f/4.7 |
| William Optics FluoroStar 120 | Triplet APO | 120 | 780 | f/6.5 | 43 | not published | 7.1 | FLAT 68III: 780 mm, f/6.5; FLAT 7A (0.8x Reducer, requires adapter): 624 mm, f/5.2 |
| William Optics FluoroStar 132 | Triplet APO | 132 | 910 | f/6.9 | 45 | not published | 9 | FLAT 68III: 910 mm, f/6.9; FLAT 7A (0.8x Reducer): 728 mm, f/5.5; FLAT 8 (0.72x Reducer): 655 mm, f/5; Ultra Flat 132 (0.79x Reducer): 719 mm, f/5.4 |
| William Optics FluoroStar 156 | Triplet APO | 156 | 1217 | f/7.8 | 43 | not published | 17 | FLAT 68III: 1217 mm, f/7.8; FLAT 7A (0.8x Reducer): 974 mm, f/6.2; FLAT 8 (0.72x Reducer): 876 mm, f/5.6; Ultra Flat 156 (0.79x Reducer): 961 mm, f/6.2 |
| Askar SQA55 | Quintuplet air-spaced Petzval APO (one SD glass, one ED glass) | 55 | 264 | f/4.8 | 44 | 55 | 1.84 | none listed on the product page |
| Askar SQA60 pro | Sextuplet air-spaced Petzval APO (2 SD glass elements) | 60 | 276 | f/4.6 | 44 | 55 | 2.79 | none listed on the product page |
| Askar SQA70 | Quintuplet air-spaced Petzval APO (2 ED glass elements) | 70 | 336 | f/4.8 | 44 | 55 | 2.68 | none listed on the product page |
| Askar SQA85 | Quintuplet air-spaced Petzval APO (2 SD glass elements) | 85 | 408 | f/4.8 | not published | 55 | 3.64 | none listed on the product page |
| Askar SQA106 | Quintuplet air-spaced Petzval APO (2 SD glass elements) | 106 | 509 | f/4.8 | 55 | 55 | 5.82 | none listed on the product page |
| Askar SQA130 | Quintuplet air-spaced Petzval APO (2 SD glass elements) | 130 | 624 | f/4.8 | 55 | 55 | 9.18 | none listed on the product page |
| Askar 65PHQ | Quintuplet air-spaced APO with two ED glass (self-flattening flat-field astrograph) | 65 | 416 | f/6.4 | 44 | not published | 2 | 65PHQ 0.75x Full-Frame Reducer: 312 mm, f/4.8 |
| Askar 80PHQ | Quadruplet air-spaced APO with two ED glass (3+1 integrated flat-field design) | 80 | 600 | f/7.5 | 44 | not published | 3.9 | 80PHQ 0.76x Full Frame Reducer: 456 mm, f/5.7 |
| Askar 107PHQ | Quadruplet air-spaced APO with two ED glass (built-in flat-field lens) | 107 | 749 | f/7 | 44 | not published | 5.7 | 107PHQ/130PHQ/151PHQ 0.7x Universal Reducer: 524 mm, f/4.9 |
| Askar 130PHQ | Quadruplet air-spaced APO with two ED glass (self-flattening) | 130 | 1000 | f/7.7 | 60 | not published | 10.5 | 107PHQ/130PHQ/151PHQ 0.7x Universal Reducer: 700 mm, f/5.4 |
| Askar 151PHQ | Quadruplet air-spaced APO with two ED glass (self-flattening) | 151 | 1057 | f/7 | 60 | not published | 11.6 | 107PHQ/130PHQ/151PHQ 0.7x Universal Reducer: 740 mm, f/4.9 |
| Askar FRA300 Pro | Quintuplet fully air-spaced Petzval APO (one ED glass) | 60 | 300 | f/5 | 44 | not published | 2.26 | none listed on the product page |
| Askar FRA400 | Quintuplet dual-ED air-spaced APO flat-field refractive astrograph | 72 | 400 | f/5.6 | 44 | 140 | 2.56 | F3.9 Full Frame Reducer for FRA400/FRA500: 280 mm, f/3.9 |
| Askar FRA400C | Quintuplet dual-ED air-spaced APO | 72 | 400 | f/5.6 | 44 | 55 | 2.68 | FRA400C 0.7x Full-Frame Reducer: 280 mm, f/3.9 |
| Askar FRA500 | Quintuplet air-spaced APO with two ED glass (flat-field) | 90 | 500 | f/5.6 | 55 | not published | 4.1 | F3.9 Full Frame Reducer for FRA400/FRA500: 350 mm, f/3.9 |
| Askar FRA600 | Quintuplet flat-field APO with two ED elements | 108 | 600 | f/5.6 | 66 | 160 | 6.5 | F3.9 Full Frame Reducer for FRA600: 420 mm, f/3.9 |
| Askar 103APO | Triplet air-spaced APO (one ED glass) | 103 | 700.4 | f/6.8 | not published | not published | 4.75 | 103APO 1x Full-frame Flattener: 700.4 mm, f/6.8; 103APO 0.8x Full-frame Reducer: 560.32 mm, f/5.44; 103APO 0.6x Full-frame Reducer: 420.24 mm, f/4.08 |
| Askar 120APO | Triplet air-spaced APO (one ED glass) | 120 | 840 | f/7 | not published | not published | 5.7 | 120APO 1x Full-frame Flattener: 840 mm, f/7; 120APO 0.8x Full-frame Reducer: 672 mm, f/5.6 |
| Askar 140APO | Triplet air-spaced APO (one ED glass) | 140 | 980 | f/7 | not published | not published | 9.2 | 140APO 1x Full-frame Flattener: 980 mm, f/7; 140APO 0.8x Full-frame Reducer: 784 mm, f/5.6 |
| Askar 160APO | Triplet air-spaced APO (one ED glass) | 160 | 1120 | f/7 | not published | not published | 11.4 | 160APO 1x Full-frame Flattener: 1120 mm, f/7; 160APO 0.8x Full-frame Reducer: 896 mm, f/5.6 |
| Askar 185APO | Triplet air-spaced APO (one ED glass) | 185 | 1295 | f/7 | not published | not published | 14.9 | 185APO 1x Full-frame Flattener: 1295 mm, f/7; 185APO 0.8x Full-frame Reducer: 1036 mm, f/5.6 |
| Askar 203APO | Triplet air-spaced APO (one ED glass) | 203 | 1421 | f/7 | not published | not published | 18.5 | none listed on the product page |
| Askar 60F Flat-Field | Quadruplet air-spaced APO with one ED glass (self-flattened) | 60 | 408 | f/6.8 | 44 | not published | 2.36 | 60F 0.75x Reducer: 311 mm, f/5.1 |
| Askar 71F Flat-Field | Quadruplet air-spaced APO with one ED glass (self-flattened) | 71 | 490 | f/6.9 | 44 | not published | 2.5 | 71F 0.75x Reducer: 369 mm, f/5.2 |
| Askar 91F Flat-Field | Quadruplet air-spaced APO with one ED glass (self-flattened) | 91 | 609 | f/6.7 | 44 | not published | 3.92 | 91F 0.75x Reducer: 455 mm, f/5 |
| Askar 111F Flat-Field | Quadruplet air-spaced APO with one ED glass (self-flattened) | 111 | 766 | f/6.9 | 44 | not published | 5.74 | 111F 0.74x Reducer: 566 mm, f/5.1 |
| Askar 131F Flat-Field | Quadruplet air-spaced APO with one ED glass (self-flattened) | 131 | 983 | f/7.5 | 44 | not published | 7.9 | 131F 0.74x Reducer: 733.6 mm, f/5.6 |
| Askar N160 | Newtonian reflector, parabolic primary, carbon-fiber tube; included 0.95x triplet corrector | 160 | 576 | f/3.6 | 28 | 55 | 3.97 | Included 0.95x MPCC (triplet corrector): 544 mm, f/3.4 |
| Askar N210 | Newtonian reflector, parabolic primary, carbon-fiber tube; included 0.95x triplet corrector | 210 | 756 | f/3.6 | 28 | 55 | 7.9 | Included 0.95x MPCC (triplet corrector): 714 mm, f/3.4 |
| Sharpstar Z4 | Sextuplet fully air-spaced APO (two ED glasses; 3 front + 3 rear elements), self-flattened | 100 | 550 | f/5.5 | 36 | not published | 4.3 | none listed on the product page |
| Sharpstar 13028HNT-AL | Hyperbolic Newtonian (PZ33 primary) with built-in two-element air-spaced corrector (one ED), aluminium tube | 130 | 364 | f/2.8 | 44 | 55 | 3.8 | none listed on the product page |
| Sharpstar 15028HNT-AL | Hyperbolic Newtonian (PZ33 primary) with built-in three-element air-spaced corrector (one ED), aluminium tube | 150 | 420 | f/2.8 | 44 | 55 | 4.8 | none listed on the product page |
| Sharpstar SCA260 (v2) | Aspherical Cassegrain astrograph: aspherical PZ33 primary, spherical secondary, 3-element air-spaced corrector | 260 | 1300 | f/5 | 80 | 70 | 14.5 | none listed on the product page |
| Sharpstar SCA310 | Cassegrain: aspherical (parabolic) primary, spherical fused-silica secondary, integrated 3" triplet corrector (one ED) | 310 | 1178 | f/3.8 | 55 | not published | 23.5 | none listed on the product page |
| Sharpstar 61EDPH III (discontinued) | Triplet air-spaced APO (two ED glass) | 61 | 360 | f/5.9 | not published | not published | 1.48 | 61EDPH III f/4.4 Full-Frame Reducer: 270 mm, f/4.4; 61EDPH III full frame flattener |
| Sharpstar 61EDPH II (discontinued) | Triplet air-spaced APO (one ED glass) | 61 | 335 | f/5.5 | 44 | not published | 1.5 | 61EDPH f/4.5 Full-Frame Reducer: 275 mm, f/4.5 |
| Sharpstar 76EDPH (discontinued) | Triplet air-spaced APO (one ED glass) | 76 | 418 | f/5.5 | not published | not published | 2.3 | 76EDPH f/4.5 Full-Frame Reducer: 342 mm, f/4.5 |
| Sharpstar 94EDPH (discontinued) | Triplet air-spaced APO (two ED glass) | 94 | 517 | f/5.5 | not published | not published | 3.3 | 94EDPH f/4.4 Full-Frame Reducer: 414 mm, f/4.4 |
| Sharpstar AL-140PH APO (discontinued) | Triplet air-spaced APO (two ED glass) | 140 | 910 | f/6.5 | not published | not published | 10.1 | 3" 0.73x reducer: 664 mm, f/4.8 |
| Sharpstar 50EDPH (discontinued) | Triplet air-spaced APO (two ED glass) | 50 | 275 | f/5.5 | not published | not published | 1.07 | 50EDPH 0.84x Reducer: 230 mm, f/4.6 |
| Sharpstar 13028HNT (carbon tube) (discontinued) | Hyperbolic Newtonian (PZ33 primary) with two-element air-spaced corrector (one ED), carbon-fiber tube | 130 | 364 | f/2.8 | 44 | 55 | 3.2 | none listed on the product page |
| Sharpstar 15028HNT (carbon tube) (discontinued) | Hyperbolic Newtonian with triplet air-spaced corrector, carbon-fiber tube | 150 | 420 | f/2.8 | 44 | 55 | 4.45 | none listed on the product page |
Sources
Manufacturer specification pages for every telescope above.
- Sky-Watcher Evostar 72ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evostar 80ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evostar 100ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evostar 120ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evostar 150DX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evostar 80EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evostar 100EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evostar 120EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evostar 150EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Evolux 82ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 80ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 100ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 120ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 150ED specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 70EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 80EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 100EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 120EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Esprit 150EDX specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher BK130PDS specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher BK150PDS specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher BK200PDS specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Quattro 150P specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Quattro 200 ST (US: Quattro 200P) specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Quattro 250 ST (US: Quattro 250P) specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Quattro 300P specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Skymax 102 specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Skymax 127 specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Skymax 150 specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Skymax 180 specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Classic 150P specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Classic 200P specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Classic 250P specifications Sky-Watcher. Accessed October 12, 2026.
- Sky-Watcher Flextube 300P specifications Sky-Watcher. Accessed October 12, 2026.
- Celestron C5 specifications Celestron. Accessed October 12, 2026.
- Celestron C6 specifications Celestron. Accessed October 12, 2026.
- Celestron C8 specifications Celestron. Accessed October 12, 2026.
- Celestron C9.25 specifications Celestron. Accessed October 12, 2026.
- Celestron C11 specifications Celestron. Accessed October 12, 2026.
- Celestron C14 specifications Celestron. Accessed October 12, 2026.
- Celestron EdgeHD 8 specifications Celestron. Accessed October 12, 2026.
- Celestron EdgeHD 9.25 specifications Celestron. Accessed October 12, 2026.
- Celestron EdgeHD 11 specifications Celestron. Accessed October 12, 2026.
- Celestron EdgeHD 14 specifications Celestron. Accessed October 12, 2026.
- Celestron RASA 8 specifications Celestron. Accessed October 12, 2026.
- Celestron RASA 11 V2 specifications Celestron. Accessed October 12, 2026.
- Celestron RASA 36 cm V2 (14-inch) specifications Celestron. Accessed October 12, 2026.
- Celestron RASA 6 specifications Celestron. Accessed October 12, 2026.
- Celestron StarSense Explorer DX 130AZ specifications Celestron. Accessed October 12, 2026.
- William Optics Cat 51 WIFD (current RedCat 51) specifications William Optics. Accessed October 12, 2026.
- William Optics RedCat 51 MK2.5 specifications William Optics. Accessed October 12, 2026.
- William Optics Cat 61 WIFD (current RedCat 61) specifications William Optics. Accessed October 12, 2026.
- William Optics Cat 71 WIFD specifications William Optics. Accessed October 12, 2026.
- William Optics RedCat 71 specifications William Optics. Accessed October 12, 2026.
- William Optics Cat 91 WIFD specifications William Optics. Accessed October 12, 2026.
- William Optics MiniCat 51 WIFD specifications William Optics. Accessed October 12, 2026.
- William Optics Ultra-Cat 56 specifications William Optics. Accessed October 12, 2026.
- William Optics Ultra-Cat 76 specifications William Optics. Accessed October 12, 2026.
- William Optics Ultra-Cat 108 specifications William Optics. Accessed October 12, 2026.
- William Optics Ultra-Cat 131 specifications William Optics. Accessed October 12, 2026.
- William Optics Mighty-Cat 71 (30th Anniversary Limited Edition) specifications William Optics. Accessed October 12, 2026.
- William Optics Pleiades 68 specifications William Optics. Accessed October 12, 2026.
- William Optics Pleiades 111 specifications William Optics. Accessed October 12, 2026.
- William Optics Pleiades 181 specifications William Optics. Accessed October 12, 2026.
- William Optics Zenithstar 61 II specifications William Optics. Accessed October 12, 2026.
- William Optics Zenithstar 73 III specifications William Optics. Accessed October 12, 2026.
- William Optics Zenithstar 81 WIFD specifications William Optics. Accessed October 12, 2026.
- William Optics Zenithstar 103 specifications William Optics. Accessed October 12, 2026.
- William Optics Gran-Turismo 71 II specifications William Optics. Accessed October 12, 2026.
- William Optics Gran-Turismo 81 IV specifications William Optics. Accessed October 12, 2026.
- William Optics Gran-Turismo 81 WIFD specifications William Optics. Accessed October 12, 2026.
- William Optics Gran Turismo 102 specifications William Optics. Accessed October 12, 2026.
- William Optics Gran-Turismo 153 specifications William Optics. Accessed October 12, 2026.
- William Optics FluoroStar 91 specifications William Optics. Accessed October 12, 2026.
- William Optics FluoroStar 120 specifications William Optics. Accessed October 12, 2026.
- William Optics FluoroStar 132 specifications William Optics. Accessed October 12, 2026.
- William Optics FluoroStar 156 specifications William Optics. Accessed October 12, 2026.
- Askar SQA55 specifications Askar. Accessed October 12, 2026.
- Askar SQA60 pro specifications Askar. Accessed October 12, 2026.
- Askar SQA70 specifications Askar. Accessed October 12, 2026.
- Askar SQA85 specifications Askar. Accessed October 12, 2026.
- Askar SQA106 specifications Askar. Accessed October 12, 2026.
- Askar SQA130 specifications Askar. Accessed October 12, 2026.
- Askar 65PHQ specifications Askar. Accessed October 12, 2026.
- Askar 80PHQ specifications Askar. Accessed October 12, 2026.
- Askar 107PHQ specifications Askar. Accessed October 12, 2026.
- Askar 130PHQ specifications Askar. Accessed October 12, 2026.
- Askar 151PHQ specifications Askar. Accessed October 12, 2026.
- Askar FRA300 Pro specifications Askar. Accessed October 12, 2026.
- Askar FRA400 specifications Askar. Accessed October 12, 2026.
- Askar FRA400C specifications Askar. Accessed October 12, 2026.
- Askar FRA500 specifications Askar. Accessed October 12, 2026.
- Askar FRA600 specifications Askar. Accessed October 12, 2026.
- Askar 103APO specifications Askar. Accessed October 12, 2026.
- Askar 120APO specifications Askar. Accessed October 12, 2026.
- Askar 140APO specifications Askar. Accessed October 12, 2026.
- Askar 160APO specifications Askar. Accessed October 12, 2026.
- Askar 185APO specifications Askar. Accessed October 12, 2026.
- Askar 203APO specifications Askar. Accessed October 12, 2026.
- Askar 60F Flat-Field specifications Askar. Accessed October 12, 2026.
- Askar 71F Flat-Field specifications Askar. Accessed October 12, 2026.
- Askar 91F Flat-Field specifications Askar. Accessed October 12, 2026.
- Askar 111F Flat-Field specifications Askar. Accessed October 12, 2026.
- Askar 131F Flat-Field specifications Askar. Accessed October 12, 2026.
- Askar N160 specifications Askar. Accessed October 12, 2026.
- Askar N210 specifications Askar. Accessed October 12, 2026.
- Sharpstar Z4 specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 13028HNT-AL specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 15028HNT-AL specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar SCA260 (v2) specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar SCA310 specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 61EDPH III specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 61EDPH II specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 76EDPH specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 94EDPH specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar AL-140PH APO specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 50EDPH specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 13028HNT (carbon tube) specifications Sharpstar. Accessed October 12, 2026.
- Sharpstar 15028HNT (carbon tube) specifications Sharpstar. Accessed October 12, 2026.