102–127 mm Maksutov on a GoTo alt-az
Sky-Watcher Skymax 127 AZ-GTi
A long focal length folded into a short tube, on a mount that finds things for you. The planetary specialist, and the most city-friendly telescope on this list.
€709seen 7 Oct 2026 at Astroshop
- 127 mmAperture
- f/11.8Focal ratio
- 8.5 kgTypical weight
- 21–254×Useful magnification
Should you buy it?
- Yes if what you mainly want is the moon and the planets: that is what this family does best.
- No if your priority is nebulae, clusters and galaxies, by eye, learn my way around the sky: other families do better for the same money.
Computed from its family's per-goal scores and its own numbers — not a rating, not one evening's opinion.
Where to buy
Also search at First Light Optics · Optique Unterlinden · Pierro Astro · Teleskop-Express (searches; neither price nor stock checked)
1 of these 5 links earn us a commission, marked above. Sorted by price, never by what pays. How this site is funded.
Prices are observed on the date shown, never live. Links marked paid link earn us a commission and cost you nothing extra.
What it shows, really
These circles are simulations, computed from the aperture, the magnification and the sky — indicative, not exact. A real night also depends on the turbulence, your eyes and your experience. Closer to the truth than the photo on the box; still not a promise.
Under a suburban sky (Bortle 6), through a common 25 mm eyepiece for wide targets and a 10 mm for planets. Every circle is the true field — nothing is enlarged.
Photo credits
These thumbnails are built from real photographs, scaled and darkened by the same arithmetic as the large view.
The numbers
Photo: Astroshop| Aperture | 127 mm |
|---|---|
| Focal ratio | 1500 mm · f/11.8 |
| Mount | AZ-GTi GoTo alt-az, driven over Wi-Fi from a phone |
| Typical weight | 8.5 kg |
| Eyepieces | 25 mm and 10 mm |
| Useful magnification | 21× to 254× at 127 mm |
| Resolution (Dawes) | 0.9″ — the tightest double star this aperture can split |
| Faintest star, suburban sky | around magnitude 11.8 |
| Observed price | €709 seen 7 Oct 2026 at Astroshop |
Made for
- The Moon and the planets
This is what the design is for. Sharp, high-contrast, and long enough to reach 250× on 127 mm (an exit pupil of 0.5 mm) without effort.
- The Sun
In white light: sunspots with their penumbra, faculae near the edge, and granulation on a steady morning. Dawes' limit on the Sun: 0.9″ (116 ÷ 127 mm, arithmetic). It needs a certified cell over the front whose range holds its 146.05 mm outside diameter: the Omegon Helievo 132 (124–148 mm), €79 (seen 26 Sept 2026). Every time: certified filter over the front · finder capped · never an eyepiece filter · an adult with children · never without the filter · measure first.
Not made for
- Nebulae, clusters and galaxies, by eye
Modest aperture and a narrow field. Globulars are fine; large nebulae are not.
- Learn my way around the sky
GoTo does the part you said you wanted to learn.
The Sun, safely
No solar filter in the box
The Sun with this model
It needs a certified cell over the front whose range holds its 146.05 mm outside diameter: the Omegon Helievo 132 (124–148 mm), €79 (seen 26 Sept 2026).
In white light: sunspots with their penumbra, faculae near the edge, and granulation on a steady morning. Dawes' limit on the Sun: 0.9″ (116 ÷ 127 mm, arithmetic).
Past about 100 to 125 mm, daytime air rather than aperture generally sets the limit on the Sun (experience: the AAVSO solar observing guide).
The listing gives a fit of 124–148 mm across the outside of the tube. Clear aperture 132 mm. The listing names no standard; no international standard exists for filters on telescopes, binoculars or lenses (AAS).
Where to buy
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Every time
- A certified solar filter over the FRONT of the instrument, fastened so it cannot slip or blow off.
- Cap or remove the finder. It is a second telescope, and it has no filter.
- Never a filter at the eyepiece end: the concentrated sunlight there can crack it in an instant.
- With children, an adult is there every time.
- Never look, or point, without the filter on. Check it before each use; a scratched or torn filter goes in the bin.
- Measure before ordering. A cell that sits loose can fall off.
Sources for the Sun
- American Astronomical Society — How to View a Solar Eclipse Safely — filters on optics go on the front; eclipse glasses never with optics; children supervised
- American Astronomical Society — Solar Filters for Optics — eyepiece filters are dangerous; the finder capped, removed or filtered; the filter attached securely
- American Astronomical Society — About the ISO 12312-2 Standard — EN ISO 12312-2:2015 covers naked-eye viewers only; no international standard covers filters on telescopes, binoculars or lenses
- Société astronomique de France — Guide des observations solaires — a filter at the front, never one screwed into the eyepiece, the finder capped
- NASA — Keep Your Eclipse Glasses to See the Sun's ‘Freckles’ — a large enough sunspot shows through eclipse glasses
- AAVSO — Le Guide d'Observation Solaire de l'AAVSO, v1.1 (2017), p. 6 — archived copy — “Les ouvertures plus grandes que 100 à 125 mm sont généralement limitées par les effets de turbulence atmosphérique”; 50 to 80 mm is enough to count sunspots
The family it belongs to: 102–127 mm Maksutov on a GoTo alt-az
What it does well
- Long focal length gives high magnification with ordinary eyepieces — ideal for planets and double stars
- Small enough to live on a shelf
- GoTo finds things a city sky hides, which is exactly where it is needed
What it costs you
- A narrow field of view. Some large objects will not fit in it at all
- Takes 30–45 minutes to cool before it performs
- The mount needs power and an alignment routine, in the dark, in the cold
Worth knowing about this model
Needs eight AA cells or a power bank. The Wi-Fi control is better than the old hand controllers and still needs a two-star alignment.
Same family, other sizes
Compare it
Read next
- Do you need a GoTo mount for a first telescope?At €500 the motor replaces half the mirror. Who that is a bad trade for, and the three people it is right for.Updated 30 Aug 2026
- Refractor or reflector for a first telescope?For the same money a reflector gives two to three times the aperture. When that decides, and the two cases where it does not.Updated 30 Aug 2026
€709seen 7 Oct 2026 at Astroshop
Where to buy