Sky-Watcher Evostar 102 OTA
Sky-Watcher Evostar 102 OTASky-Watcher Evostar 102 OTASky-Watcher Evostar 102 OTA

Sky-Watcher Evostar 102 OTA

Now: £206.10 (Save:  £22.90) Was:  £229.00
  (2 Reviews)
✓ 2 year warranty


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About this product

Model:  SWevo102ota
Part Number:  10740

This long focal length 4-inch f10 achromat refractor is the quintessential telescope for astronomy. 

A good choice for observing the Moon, solar system targets and brighter deep sky objects. 

Views are clear and sharp with high contrast. Chromatic aberration is also surprisingly well-corrected. 

Fitted with a 2" focuser and includes a 2" Star Diagonal, two Plossl eyepieces and a 1.25"/2" eyepiece adapter (so it accepts both 1.25" & 2" eyepieces). 

A 6x30 optical finderscope, tube-rings and a Sky-Watcher/Vixen type dovetail are also included. 

For photography, it has a convenient direct SLR connection. 


Features & specifications: 

Air-spaced Doublet Optics

Direct SLR Camera Connection

6x30 Finderscope

Dual-Fit 1.25"/2" Focuser

2"/50.8mm Star Diagonal

Multi-Coated Objective Lens

28% more Light Gathering than 90mm

Eyepieces Supplied (1.25"): 10mm & 25mm

Magnifications (with eyepieces supplied): x40 & x100

Highest Practical Power (Potential): x204

Objective Lens Diameter: 102mm

Telescope Focal Length: 1000mm (f/9.8)



Customer reviews

Average Rating (2 Reviews):  
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Rating (max 5):  
A good all-rounder
15 April 2024  | 

I bought this 102mm Evostar mainly with the intention of having a telescope which would be suited to solar observation by eyepiece projection or with a filter over the objective, but I've found it useful as a reasonably light instrument which doesn't need a very heavy mount and can be set up quickly when there's no need for a heavier, more sophisticated model. Due to the weather, the initial tests had to be on a terrestrial subject, the details on the roofs of distant houses. Definition was good, with noticeably less chromatic aberration than its short-focus counterpart which I've had for a few years. It shows as a slight purple fringe on high-contrast edges at high magnification beyond about 80x, but the underlying image is sharp, and the purple haze isn't intrusive. Looking at dark roofs against a bright sky seems to be a fairly rigorous test; the degree of false colour which is apparent is often harder to see on astronomical subjects, and this is the case here. When I was finally able to view the moon, the CA on the limb and terminator was practically invisible at 120x. There was nothing very obvious on bright stars, either. The focusing rack and pinion are basic, but adequate; the only thing I would really really criticise on the telescope is the usual Skywatcher sticky grease on the focusing mechanism, which gets everywhere, including fingers, and is hard to remove. One of the first things I did was to clean it all off. The focusing is none the worse for this, and fine focusing is actually easier, as there's less drag. If the small tensioning grub screws on the focusing mount are carefully adjusted, there's no need of grease to give an acceptably smooth action. The 2 inch eyepiece mount is a good feature; not all 102mm telescopes have it, and it allows reasonably wide angles of view with a low power 2" eyepiece, for star clusters and large nebulae. I think a four star rating is appropriate for this model. Performance and mechanical quality are obviously not in the class of apo or ED telescopes, but then, nor is the price, and I can't think of anything (except the grease!) which should discourage anyone from buying it.

Rating (max 5):  
Can't really fault it
20 December 2023  | 

My first proper telescope was a Vixen 102mm achromat, so when I needed a scope for viewing the Moon and planets, this was an obvious candidate. My ST120 refractor disappointed with its copious chromatic aberration (but great for comet hunting). The focuser supplied was usable but I fitted the excellent Astro Essentials Crayford focuser I bought for the ST120. The 2-inch diagonal was surprisingly good optically so I've kept it. Using a Baader Fringe Killer eyepiece filter I'm getting terrific views of the Moon and Jupiter with almost zero CA and the image is sharper than that through the ST, possibly due to lower spherical aberration with the f9.8 focal ratio as it seems to use the same Littrow doublet design of objective lens. Even the notorious Kellner eyepieces aren't nearly as bad with the long focal length as they are with an f5 scope. Great kit at a silly price!


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