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Astronomical Telescope Comparison: 23 Scopes Compared! Includes: Celestron C60, Celestron SP-C80, C90 Astro, Celestron Omni XLT 102, Celestron Omni XLT 102ED, Celestron Omni XLT 150, Celestron SP-C6, Celestron C6-A-XLT, Celestron C8-A-XLT, Meade ETRS-90, Meade 114mm Reflector, Skywatcher BK1021EQ3-2, Skywatcher BKP15075NEQ3, Stellarvue SV80ST, Stellarvue SV90T, Stellarvue SV102ED, Stellarvue SVR105-3 Raptor, Stellarvue SV115T, Stellarvue SV160, Vixen A80Mf, Vixen A105M, Vixen R150S and Vixen VC200L By the Astronomy and Photography Online Staff This is a comparison of commercially made, portable, astronomical telescopes. These are telescopes you can take into the field and use on portable mounts, not permanently mounted observatory telescopes. Portability is a subjective matter, but for our purposes an optical tube assembly (OTA) should not weigh more than about 21 pounds or exceed 9.25" of clear apreture. This article is concerned only with the optical tube assembly, not the merits of the mounting system that is available for, or supplied with, the OTA. The mounting system is as important as the OTA, but mounts are dealt with in other articles and most telescopes can be adapted to a variety of mounts. Beware of optically good scopes that are sold with integral mounts (usually some sort of fork mount) of inferior quality, such as the Meade ETX-90. This is a subjective comparison by reasonably experienced observers. It reflects our consensus opinion about individual telescopes with which we are familiar or have reviewed. The basic criteria are simple: our observations of the night sky, viewing common planetary and deep sky objects. This is the same basic method used by amateur astronomers around the world to compare and evaluate their telescopes. We view a variety of objects with all of our telescopes, including the moon and planets, single and double stars, open star clusters, globular star clusters, galaxies, nebula and the like. Optically, getting the best views of relatively bright objects, such as the moon, planets, open star clusters and splitting double stars, emphasizes resolution, contrast and optical correction. Observing dim deep sky objects, especially nebulas and galaxies, primarily emphasizes light grasp. (As deep sky observers like to say, "Aperture rules.") All telescopes are the result of a series of design and production compromises. No telescope combines the best of all possible worlds. Rather that try to grade individual optical qualities like resolution, contrast, light grasp, residual aberrations and so forth separately, we have simply rated the telescopes in terms of their clear aperture, general optical quality, build quality and construction, focusing ease and precision, planetary observing capability, deep sky observing capability and visual quality. Our scoring is done on a numerical 1-10 scale, where 1 is the lowest score, 4-6 is the average range and 10 is the top rating. Here is a brief explanation of our comparison scoring and criteria. Category/User Level: Beginner, Intermediate, Advanced, Expert. Clear aperture: One point per inch up to 9.25". (Scopes over 9.25" are not included in this comparison.) Optical quality: Compared to other telescopes of the same aperture and basic design (refractor, reflector or catadioptric); among refractors, for example, a department store scope would be "1" (poor) and a top quality APO triplet would be "10" (excellent). Physical quality and construction: A department store telescope would be a "1" (poor) and a Questar would be a "10" (excellent). Focusing ease and precision: 1 (focuser slips, gritty or hard to focus), 2 (focus by turning the lens barrel), 4 (1.25" standard rack and pinion focuser or typical SCT), 6 (2" single speed Crayford or refined rack and pinion focuser), 8 (2" dual speed Crayford focuser), 10 (2" dual speed Feathertouch reverse Crayford focuser). These are general guidelines for typical focusers, so individual scores may vary. Deep sky observing: 1 (60mm refractor), 3 (75-80mm refractor or 90mm reflector), 5 (4" refractor or 4.5-5" reflector), 6 (4.5-5" refractor or 6" reflector), 7 (5.5" refractor or 7" reflector) 8 (6" refractor or 8" reflector), 9 (9" reflector). These are general aperture guidelines for observing that assume very good optical quality and a medium (f/8-f/11) focal ratio. Individual telescope scores may vary. Planetary observing: Similar in concept and aperture to the Deep Sky rating, but long focal length, high magnification capability, superior resolution and high contrast are important factors. Visual quality: Image quality as (subjectively) seen by the human eye compared to all other scopes of similar aperture, regardless of type, and given a numerical rating. APO triplet refractors will typically score highest (10) in this category. Overall ranking: Averaging the scores of the Astronomy and Photography Online staff members and using our matrix, we rated the telescope with the highest point total in the comparison #1, the second highest score #2 and so on. The overall rank list is at the end of this article. Here are the telescopes, with ratings, listed alphabetically by brand: Celestron 60 (60LCM, C60)
Celestron C80 (Discontinued, made in Japan by Vixen)
Celestron C90 Astro (Discontinued, made in USA)
Celestron Omni XLT 102
Celestron Omni XLT 102ED
Celestron Omni XLT 150
Celestron SP-C6 (Discontinued, made in Japan by Vixen)
Celestron C6-A XLT
Celestron C8-A XLT
Meade ETX-90
Meade 114mm Reflector (AZ, EQ, DS series)
Skywatcher BK1021EQ3-2
Skywatcher BKP15075NEQ3
Stellarvue SVR80ST2
Stellarvue SV90T
Stellarvue SV102ED
Stellarvue SVR105 (FT) Raptor
Stellarvue SV115T (FT)
Stellarvue SV160 (FT)
Vixen A80M, A80Mf
Vixen A105M
Vixen R150S (Discontinued)
Vixen VC200L
Here are the overall rankings of all the telescopes compared in this article according to our matrix. This is an averaged score based on adding the points for Clear aperture, Optical quality, Physical Quality, Focusing and Visual quality categories. Figuring that observing is the point of owning a telescope, we gave the "Planetary" observing category 2x weighting (multiplied the score by two) and the "Deep sky" observing category 3x weighting (multiplied the score by three) to reflect what we consider normal astronomical use. "Aperture rules," so we gave 4"-5" scopes a one point bonus, 6"-7" scopes a two point bonus and 8"-9.25" scopes a three point bonus. Our rankings do not consider price; we have no way of knowing our readers' price range. Tie breakers, if necessary, are (1) aperture and (2) focal length. Weighting the categories differently will alter the results shown here. For example, a dedicated deep sky observer might give the "Deep sky observing" score a 2x weighting, but not the "Planetary Observing" score. A dedicated planetary observer might do the opposite. If points were awarded for lower price, the expensive scopes would drop in the ratings. Another person might consider the optical quality more important than the focuser, or change the point scale from arithmetic to a geometric or exponential progression. There is practically no limit to how an individual might weight the matrix.
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