ZWO · China
ZWO Seestar S50 Pro
The heaviest overhaul in the Seestar range. The dual-band and the equatorial mode were already there; what changes is the sensor, the optics, the battery and the price.
At three-quarters on its tripod, tube raised
≈ €999
≈ €899 as a launch offer until 15 September 2026 at 9:00, Central European Summer Time
List price recorded in 2026, excluding promotions and accessories. It is not an offer. The price offered to you arrives in writing.
This device can be ordered from me. No basket and no online payment: the price, the lead time and availability arrive in writing. I have never had it in my hands. That is written further down this entry, and I am not going to tell you otherwise in order to sell it to you.
The device photographs are the manufacturers' official images. UST is an authorised reseller for all five brands. No image comes from a competing reseller.
not tested In this catalogue: no shots at all. Entry built on public sources.
0 · aucune donnée de première main
0 towards 165h · hours I have logged with this device, this is not a rating
For the image the l'Origin makes in 1h, it takes 5h 35m here.
This equivalence says nothing but speed. It says nothing about resolution, about the field, or about optical quality. f/2,2 on 152 mm and f/5,2 on 50 mm do not photograph the same objects. The calculation takes nothing but the published focal ratios, with sensor, sky and target held identical.
Rapport d'ouverture : the focal length divided by the diameter, written f/, and the smaller that number, the faster the image forms.
- Aperture
- 50 mm (telephoto) · 3.4 mm (wide angle)
- Focal length
- 260 mm (telephoto) · 6 mm (wide angle)
- Focal ratio
- f/5.2
- Sensor
- OmniVision OS08B10 (telephoto, 1/1.2 inch, 2.9 µm photosites) · Sony IMX586 (wide angle)
- Resolution
- 2,160 × 3,840 px on the telephoto (8.3 Mpx)
- Mount
- Motorised altazimuth, equatorial mode supported
- Weight
- 2.8 kg (main unit)
- Software
- Seestar (iOS, Android)
- Indicative price
- ≈ €999 (≈ €899 as a launch offer until 15 September 2026 at 9:00, Central European Summer Time)
Monture azimutale : it moves in altitude and in rotation, but the field turns during the night. Monture équatoriale : one axis set on that of the Earth, so that the field no longer turns.
The device
Seen from closer up
The other images published by ZWO for this device.
Where it excels
What it does well
The serious deep sky at a contained price. Fifty millimetres, a large sensor and nine hours of battery: it holds a whole night with no top-up.
Strong points
- The telephoto sensor goes from 1/2.8 inch to 1/1.2 inch, and the resolution from 2.1 to 8.3 Mpx.
- Apochromatic four element lens with ED glass, against three on the S50.
- A 3.4 mm wide angle lens at f/1.75, absent from the original S50, which frames 63° at one go.
- 10,000 mAh battery quoted at nine hours, against 6,000 mAh and six hours on the S50.
- 128 GB of onboard storage, twice the S50. ZWO writes that a hundred or so gigabytes are really available.
- It speaks the open ASCOM Alpaca protocol and plugs into N.I.N.A. No other device in the panel does.
- Dual-band filter as standard and solar filter supplied, as on the original S50.
Weak points
- The price doubles: about €999 at the recommended rate, against €499 for the original S50 from the same manufacturer.
- 50 mm of aperture, unchanged. The diameter does not move.
- 2.8 kg for the main body, against 2.5 kg on the S50. It is getting heavier.
- The launch price has a date on it: it drops on 15/09/2026 at 9h, and the manufacturer's recommended rate is €999.
- It is sold on pre-order. ZWO quotes shipping in about three to four weeks.
- Nothing can be changed and nothing added: neither optics, nor sensor, nor mount.
In practice
Starting out, observing, setting up
-
01
The focal ratio printed here is the one ZWO publishes, f/5.2. The calculation on the published 50 mm and 260 mm lands on it.
-
02
The dual-band filter and the equatorial mode are not new: the original Seestar S50 already carried both, with the same passbands and the same note about the mount. What changes here is the sensor, the optics, the battery and the storage.
-
03
Equatorial mode is chosen in the app before the session. It is what allows long exposures.
-
04
The storage quoted is 128 GB, of which a hundred or so really available: ZWO writes it itself on its datasheet.
-
05
The three internal filters are the dual-band, an ultraviolet and infrared cut, and a dark frame filter. The solar filter, for its part, is magnetic and external.
-
06
The price printed here is the one from the manufacturer's European shop, in euros, shipped from Germany, VAT included.
Images made with this device
No images: it has not been tried
This device has never been used to make one of my images. The photographs above show the device, and they come from the manufacturer. No sky image is borrowed to fill the space. Its entry rests on the published sources, listed further down. Its integration time scale therefore stays at zero.
Temps d'intégration : the total exposure time, the sum of every exposure stacked on an object.
0 images · space left empty
I publish 10 photographs, 2 of which are of equipment. None of them appears on this entry, and that is deliberate: not one of them shows this device, and an image placed there would amount to a claim.
Compare it
Head to head with another device
Each page sets the two entries line by line and works out the differences. It writes at the top which of the two was used to make my images.
Getting hold of one
Order this Seestar S50 Pro
≈ €999 (≈ €899 as a launch offer until 15 September 2026 at 9:00, Central European Summer Time)
Market price recorded in 2026 from the sources cited below. It is not a selling price, and it does not constitute an offer. Your price, your lead time and availability appear in the written reply.
Say what you want to photograph, and from what sky. The answer says whether this device suits. If not, it says which one suits better. Are you looking for a second-hand one, or do you have a device to trade in? Write it in the message. The answer will be straight, including when it is no.
Sources
Where these figures come from
- ZWO Seestar, fiche officielle du Seestar S50 Pro
- ZWO Seestar, boutique européenne, prix en euros TTC et date de fin de l'offre
- ZWO Seestar, fiche du Seestar S50 d'origine, pour la comparaison
The prices are indicative and recorded in 2026. A specification wrong or out of date? Report it. The field of view and the sampling are not published here. The physical size of the sensor is not part of the project's sourced data, and those two values cannot be estimated.