ZWO Seestar S50 Pro
ZWO's compact refractor, dual-band filter and two camera fields
At a glance
Good seeing6.4 out of 10
Its 9-hour battery life and wide-angle camera field of view are strengths, while its 50 mm (2 in) aperture gathers less light than most of the telescopes compared.
Five scores, from 1 to 10
- Light graspaperture, against every scope listed here4.4
- Detailfocal length and pixel size4.2
- Field of viewhow much sky fits in one frame7.5
- Portabilitycarry weight, without the tripod6.4
- Easebattery, autofocus, dew heater, light pollution handling9.5
Mean score 6.4 out of 10
The sums behind these figures are set out on how scores work. With no figure from the maker, a row stays empty.
Compared with Unistellar
Unistellar eQuinox 2
£2,299Price at Unistellar's UK shop, 23 October 2026
| Spec | ZWO Seestar S50 Pro | Unistellar eQuinox 2 |
|---|---|---|
| Aperture | 50 mm | 114 mm |
| Weight | 2.8 kg | 7 kg |
| Sensor | 8.3 MP | 6.2 MP |
See the price at UnistellarRead the Unistellar eQuinox 2 page
Seestar S50 Pro specifications
The 2.8 kg main unit, according to the maker, is the weight to carry into your garden, with the tripod excluded. This is a ZWO smart telescope built around a refractor, with its optics and cameras controlled through the Seestar app. Its compact weight makes carrying the telescope a distinct consideration, while the stated figure applies to the main unit alone.
The 50 mm (2 in) aperture gathers less light than most of the telescopes compared. Its light grasp therefore sits lower in this group, based on the aperture ordering used for the comparison. For your observing plans, that is the central optical trade-off to weigh against the two camera views and the built-in filters.
The 260 mm focal length and f/5.2 focal ratio describe the refractor's optical arrangement. The telephoto camera uses an OmniVision OS08B10 image sensor, while the wide-angle camera uses a Sony IMX586. ZWO quotes 8.3 MP, a pixel size of 2.9 µm and image resolution of 2160 x 3840 pixels. The pixel size and focal length put its finer-detail position behind most compared telescopes, using the more limiting of optical resolving power and two-pixel sampling.
The field of view is 2.8° in portrait orientation for the telephoto camera and 63° in portrait orientation for the wide-angle camera, according to the maker. The broad camera field gives the S50 Pro a wider sky framing than most instruments compared, with the comparison based on the longest side of the main camera's field. These are separate camera views, so the telephoto and wide-angle figures describe different framing options rather than a single interchangeable field.
Mount, filters and observing setup
The alt-azimuth mount includes an equatorial mode, giving you two stated mounting modes for setting up the telescope. Long exposures on an alt-azimuth mount can show field rotation, so the equatorial mode is relevant when planning longer imaging sessions.
The built-in filters comprise a UV/IR-cut filter, a dual-band light pollution filter and a dark-frame filter for the telephoto camera. The dual-band filter combines OIII at 30 nm and Ha at 20 nm, and is intended to help with imaging emission nebulae under light pollution. Filter choice gives you a way to tailor the telephoto imaging setup to the target, though a filter does not remove the effects of a bright garden sky.
The battery life is 9 hours, according to the maker, and the internal storage is 128 GB. Those figures set the stated power duration and space available for imaging files, without implying a particular session length or number of saved images. The Seestar app is the control point for this smart telescope, bringing the mount, refractor and camera system into one app-based setup.
- Light grasp: Sits towards the lower end among the telescopes compared, with a 50 mm aperture.
- Detail: Falls behind most compared telescopes, based on the 260 mm focal length and 2.9 µm pixels.
- Field: Frames a broader patch than most of the compared instruments, with a 2.8° telephoto field in portrait orientation.
- Portability: Is lighter to carry than most compared telescopes, at a maker-quoted 2.8 kg for the main unit.
- Ease: Runs for longer than most compared telescopes on this measure, combining 9 hours of maker-quoted battery life with its built-in light pollution filter.
See it at Seestar (ZWO)ZWO Seestar S50 Pro, £999, Typical UK retail price, 23 October 2026
Specifications
| Optical design | Refractor |
|---|---|
| Aperture | 50 mm (2 in) |
| Focal length | 260 mm |
| Focal ratio | f/5.2 |
| Sensor | OmniVision OS08B10 (telephoto); Sony IMX586 (wide), 8.3 MP |
| Pixel size | 2.9 µm |
| Image size | 2160 × 3840 px |
| Field of view | Tele: 2.8° (Portrait); Wide: 63° (Portrait) |
| Limiting magnitude (maker's figure) | not stated by the maker |
| Mount | Alt-azimuth, with an equatorial mode |
| Electronic eyepiece | not stated by the maker |
| Filters built in | UV/IR-cut, dual-band light pollution OIII 30 nm / Ha 20 nm (telephoto), dark frame (telephoto) |
| Autofocus | not stated by the maker |
| Battery life (maker's figure) | 9 h |
| Weight | 2.8 kg |
| Storage | 128 GB |
| Dew heater | not stated by the maker |
| Weather rating | not stated by the maker |
| App | Seestar app |
Source: the maker's own specification sheet. Where it says "not stated by the maker", the maker has not given that figure so far.
Versions
Typical UK retail price, 23 October 2026. Each row leads to that version at the shop.
Strengths and limits
- The 50 mm (2 in) aperture, 260 mm focal length and f/5.2 focal ratio are paired with an OmniVision OS08B10 telephoto image sensor and a Sony IMX586 wide-angle image sensor, according to the maker.
- The maker states a 2.8° field of view in portrait orientation for the telephoto camera and 63° for the wide-angle camera.
- According to the maker, battery life is 9 hours, internal storage is 128 GB and weight is 2.8 kg for the main unit.
- The 50 mm (2 in) aperture gathers less light than most of the telescopes compared.
- The 260 mm focal length and 2.9 µm pixel size resolve coarser detail than most of the telescopes compared.
Who it suits, and which skies
For first nightsFor town skiesGrab and go
A good match if you want an app-controlled smart telescope, a wide-angle camera alongside the telephoto camera, or a stated 9-hour battery life.
Bundles and prices for each version sit in the table above; the current line-up is on the shop's own page.
Questions about the ZWO Seestar S50 Pro
- How much weight do you need to carry?
- The maker states a weight of 2.8 kg for the main unit.
- How long can you use it before recharging?
- According to the maker, battery life is 9 hours.
- Does it have a filter for a city sky?
- The maker lists a built-in dual-band light pollution filter for the telephoto camera, with OIII at 30 nm and Ha at 20 nm.
Photos
Last light
The maker lists a 50 mm (2 in) aperture, 260 mm focal length, f/5.2 focal ratio and 2.9 µm pixel size. A 2.8° telephoto field of view sits alongside a 63° wide-angle field of view, both in portrait orientation, according to the maker. Its 9-hour battery life, dual-band light pollution filter and equatorial mode give you a clearly specified set of features.
See it at Seestar (ZWO)£999, Typical UK retail price, 23 October 2026
Field notes that mention it
Nearby in the sky: similar scopes
- Vaonis Vespera II50 mm, 5 kg, 2.5° × 1.4°, from £1,398
- Vaonis Vespera III50 mm, 5 kg, 2.5° × 1.4°, £2,199
- DwarfLab Dwarf 335 mm, 1.35 kg, 3°, from £459
- ZWO Seestar S30 Pro30 mm, 1.65 kg, Tele: 4.6°; Wide: 63°, £649