A long focal length folded into a short tube
A catadioptric telescope uses a mirror and a correcting lens together, and folds the light path so that a long focal length fits inside a short tube. A Schmidt-Cassegrain or a Maksutov of two meters of focal length is barely longer than an arm, which is why these are the tubes that travel and the tubes that sit on a balcony. The long focal length makes them natural planetary and lunar instruments: high magnification comes from ordinary eyepieces rather than from extreme ones. Three properties come with the folding. Cool-down is the first and the most often ignored — a closed tube with a thick corrector holds the warmth of the house, and the image will not settle until the glass has reached the outside temperature. The second is the corrector plate itself, which faces the sky and collects dew before anything else on the instrument does. The third is back focus: the focuser works by moving the primary mirror, so the distance behind the tube where an image forms is generous, and it is what makes these tubes so adaptable to cameras, reducers and diagonals. Read which of the two designs is in front of you — a Maksutov usually carries a smaller obstruction and a slower ratio, a Schmidt-Cassegrain a larger aperture for the money. We compare aperture, folded focal length and ratio, corrector design, obstruction, back focus, cool-down guidance, tube weight and mount supplied.
100 mm (3.94 in) Maksutov · 1400 mm (55.1 in) focal length · f/14 · EQ3 equatorial mount
A 100/1400 Maksutov-Cassegrain on an EQ3 equatorial mount, supplied with a 25 mm Plössl eyepiece (56x), a 90° star diagonal and a smartphone holder.
Best for: Moon, planets and double stars from a town, on a mount with real slow-motion controls
≈ $734
127 mm (5 in) Maksutov-Cassegrain · AZ-GTi Wi-Fi GoTo mount · 11 lb payload · mount 8.6 lb
Sky-Watcher's SkyMax 127 Maksutov-Cassegrain on the AZ-GTi, a Wi-Fi GoTo alt-azimuth mount controlled from a phone, with an 11 lb payload, Freedom Find encoders and an aluminum tripod.
Best for: Lunar, planetary and double-star observing from a small or awkward site, driven from a phone
≈ $839
102 mm (4 in) Maksutov-Cassegrain · 1325 mm at f/13 · GoTo fork with built-in wedge · 21 lb with tripod
Celestron's NexStar 4SE: a 4-inch Maksutov-Cassegrain with StarBright XLT coatings on a computerized single-arm GoTo mount whose tripod has a built-in wedge, 21 lb with tripod.
Best for: A first computerized telescope for the Moon and planets that can also take short-exposure photos
≈ $649
6-inch (150 mm) Schmidt-Cassegrain · computerized GoTo single-arm mount · 40,000+ objects · SkyAlign
Celestron's NexStar 6SE: a 6-inch Schmidt-Cassegrain on a computerized single-arm GoTo mount with the NexStar+ hand control, a 40,000-object database and SkyAlign.
Best for: Six inches of aperture on a mount that finds things, for an observer who will look rather than photograph
≈ $1,039
6-inch (150 mm) Schmidt-Cassegrain · 1500 mm at f/10 · Advanced VX German equatorial with PEC · 7° to 77° latitude
Celestron's Advanced VX 6-inch Schmidt-Cassegrain: a 1500 mm f/10 tube with StarBright XLT coatings on a computerized German equatorial mount with periodic error correction, usable from 7° to 77° latitude.
Best for: Imaging from a fixed site, where the mount matters more than the tube
≈ $1,699
6-inch (150 mm) Schmidt-Cassegrain · integrated Wi-Fi · 10-hour built-in battery · 354x highest useful magnification
Celestron's NexStar Evolution 6: a 6-inch Schmidt-Cassegrain on a single-arm GoTo mount with integrated Wi-Fi, a built-in lithium battery rated for 10 hours, brass worm gears and 40 mm and 13 mm eyepieces.
Best for: A six-inch that runs all night on its own battery and is driven from a phone
≈ $1,618
60 mm (2.36 in) Maksutov · 750 mm (29.5 in) in a 200 mm (7.87 in) tube · full-size tripod · finder · plastic tube
Sarblue's upgraded Mak60: a 60 mm Maksutov-Cassegrain with 750 mm of focal length in a 200 mm plastic tube, on a full-size tripod with a finder scope, a 20 mm eyepiece and a phone mount.
Best for: A first telescope that has to stand on its own tripod and be aimed with a finder
70 mm (2.76 in) Maksutov · 1000 mm (39.4 in) in a 210 mm (8.27 in) tube · f/14.3 · slow-motion tripod, 23 to 56 in
Sarblue's Mak70: a 70 mm Maksutov-Cassegrain with 1000 mm of focal length in a 210 mm aluminum tube, on a slow-motion tripod adjustable from 23 to 56 inches, with 20 mm and 10 mm eyepieces.
Best for: Lunar and planetary detail from a tripod that can be raised to standing height
≈ $180
60 mm (2.36 in) Maksutov · 750 mm (29.5 in) in a 200 mm (7.87 in) tube · 37.5x with the 20 mm · focuses from 8 m (26 ft)
Sarblue's Mak60 tabletop kit: a 60 mm Maksutov-Cassegrain with 750 mm of focal length in a 200 mm tube, a 20 mm eyepiece, an erect-image diagonal, a phone adapter and a tabletop tripod.
Best for: A compact first telescope that doubles as a spotting scope, used from a table
≈ $100
8-inch (203 mm) Schmidt-Cassegrain · computerized GoTo single-arm mount · 40,000+ objects · SkyAlign
Celestron's NexStar 8SE: an 8-inch Schmidt-Cassegrain with StarBright XLT coatings on a computerized single-arm GoTo mount, with the NexStar+ hand control, a 40,000-object database and SkyAlign.
Best for: Serious aperture that still fits in a car trunk and sets up in minutes
≈ $1,499
Aperture remains the decisive quantity, and the catadioptric formula is the one that fits it into the shortest tube.
Tube weight decides the mount required and the ease of setting up, which is the real brake on going out.
An instrument that combines mirrors with a corrector lens to fold a long focal length into a short tube.
A closed tube takes time to reach outside temperature. Published cool-down guidance is the maker’s.
The distance available behind the instrument for inserting accessories while keeping focus. It is published.
It is a consequence of the optical formula. The published percentage allows two instruments to be compared.
Mount supplied is published entry by entry. Many tubes are sold on their own.
The optical family chosen, published by the maker. It explains the behavior and the price.
Guidance is specific to each model and sits in the manual. This site describes no procedure.
Because it depends on the eyepiece. Published folded focal length is what lets you calculate it.
A catadioptric buys compactness and pays for it in obstruction and cool-down time. Back focus decides everything that can be hung behind it.
The column is shown only when four instruments in five publish the figure. Below that, it would be comparing the absence of numbers.
| Model | Price | Aperture | Corrector design | Mount supplied |
|---|---|---|---|---|
| Sarblue Mak60 with tabletop tripod (SBMak01) | $100 | 60 mm (2.36 in), stated | Maksutov-Cassegrain · fully multi-coated optical glass, stated | Tabletop tripod · 20 mm eyepiece (37.5x, stated) · erect-image diagonal · phone adapter · detachable lid showing the inside |
| Sarblue Mak70 (MAK) | $180 | 70 mm (2.76 in), stated | Maksutov-Cassegrain · fully multi-coated · high-reflectivity coating stated not to oxidize easily | Slow-motion tripod adjustable from 23 to 56 in · 3/8 in or 1/4-20 threaded post for a field tripod · 20 mm eyepiece (50x) · 10 mm eyepiece (100x) · phone mount with 1.5x Barlow · adjustable 5x24 finder |
| Celestron NexStar 4SE (11049) | $649 | 102 mm (4 in), stated as 4-inch | Maksutov-Cassegrain · StarBright XLT coatings, the first Maksutov from Celestron to carry them, stated | Computerized single-arm GoTo mount · NexStar+ hand control with 40,000+ objects · SkyAlign · tripod with built-in wedge · DSLR camera-control feature |
| Bresser FirstLight 100/1400 Maksutov | $734 | 100 mm (3.94 in), stated | Maksutov-Cassegrain (meniscus corrector), stated | EQ3 equatorial mount · 25 mm Plössl eyepiece (56x, stated) · 90° star diagonal · smartphone holder |
| Sky-Watcher SkyMax-127 AZ-GTi | $839 | 127 mm (5 in), stated | Maksutov-Cassegrain · borosilicate primary and secondary mirrors with quartz overcoat, 94% reflectivity · corrector with Metallic High-Transmission Coatings (MHTC), stated | AZ-GTi Wi-Fi GoTo alt-azimuth mount · SynScan Pro app · 11 lb (5 kg) payload · Freedom Find dual encoders · aluminum tripod with pier extension · 3/8-16 thread for photo tripods · SNAP port for timed DSLR exposures |
| Celestron NexStar 6SE (11068) | $1039 | 6 in (150 mm), stated | Schmidt-Cassegrain, stated | Computerized single-arm GoTo mount · NexStar+ hand control with 40,000+ objects · SkyAlign · compatible with StarSense AutoAlign, SkyPortal WiFi and SkySync GPS accessories |
| Celestron NexStar 8SE (11069) | $1499 | 8 in (203 mm), stated | Schmidt-Cassegrain · StarBright XLT coatings | Computerized single-arm GoTo mount · NexStar+ hand control with 40,000+ objects · SkyAlign and Solar System Align · red-dot finder · 25 mm eyepiece |
| Celestron NexStar Evolution 6 (12090) | $1618 | 6 in (150 mm), stated | Schmidt-Cassegrain · StarBright XLT coatings, stated | Single-arm alt-azimuth GoTo mount with brass worm gears · integrated Wi-Fi with the SkyPortal app (120,000+ objects) · NexStar+ hand control included · built-in lithium-ion phosphate battery, up to 10 hours · manual clutches on both axes · stainless steel tripod · StarPointer finder · 1.25 in diagonal |
| Celestron Advanced VX 6" Schmidt (12079) | $1699 | 6 in (150 mm), stated | Schmidt-Cassegrain · StarBright XLT coatings, stated | Advanced VX computerized German equatorial · periodic error correction (PEC) · usable from 7° to 77° latitude · tracks across the meridian · NexStar+ hand control · All-Star Polar Alignment · 20 mm eyepiece · 6x30 finder |
| Sarblue Mak60 with full-size tripod | — | 60 mm (2.36 in), stated | Maksutov-Cassegrain · fully multi-coated optics, stated | Full-size adjustable tripod · finder scope · 20 mm eyepiece (37.5x, stated) · universal phone mount · detachable lid showing the inside |
$100 – $649
3 models
Sarblue Mak60 with tabletop tripod (SBMak01), Sarblue Mak70 (MAK), Celestron NexStar 4SE (11049)
$734 – $1039
3 models
Bresser FirstLight 100/1400 Maksutov, Sky-Watcher SkyMax-127 AZ-GTi, Celestron NexStar 6SE (11068)
$1499 – $1699
3 models
Celestron NexStar 8SE (11069), Celestron NexStar Evolution 6 (12090), Celestron Advanced VX 6" Schmidt (12079)
Specifications: manufacturer sheets for telescopes and observing optics and the matching Amazon product pages. Prices and availability: Keepa. Every figure in this table names its source.
Most recent revision in this category: November 7, 2026.
Any figure written into the body of this page was true on the day it was written. The amount shown next to each instrument is requested from the retailer as the page loads, and it is that amount, not the text, that stands.
