Seestar (ZWO) · Out of stock at official store · launched 2023
Seestar S50 review: specs, price and verdict
The 50 mm telescope that made smart telescopes mainstream: big aperture for the money, tiny 2 MP sensor, narrow field.
Out of stock at the official store when we checked (11 Nov 2026).
- 50 mmaperture
- 1.29° × 0.73°field of view
- 2.39″per pixel
- 2.5 kgweight
- 6 hbattery
Our verdict
Still a capable deep-sky camera, but with the S50 Pro shipping at $999 and the S30 Pro at $699, a new S50 only makes sense below its old $499 list price.
Best for: Buyers who find one in stock at a discount and want the most aperture under $500.
Pros
- 50 mm aperture gathers 2.8× the light of the 30 mm Seestars
- Finest image scale of any Seestar except the S50 Pro (2.39″/px)
- Built-in duo-band filter and dew heater
- EQ mode supported
Cons
- 2.1 MP 1080p sensor, portrait-only frame
- Narrow 1.29° × 0.73° field: Andromeda needs a mosaic
- No wide-angle camera
- Out of stock at the official store
What fits in the field of view
The S50 telephoto camera frames 1.29° × 0.73° of sky. Below, its frame (gold) is drawn to scale over three popular targets.
| Object | With the S50 |
|---|---|
| Full Moon | Fits (40% of the frame width) |
| Andromeda Galaxy (M31) | Needs a mosaic (about 3×2 frames) |
| Orion Nebula (M42) | Needs a mosaic (about 2×2 frames) |
| Pleiades (M45) | Needs a mosaic (about 2×3 frames) |
| North America Nebula | Needs a mosaic (about 2×3 frames) |
| Whirlpool Galaxy (M51) | Fits (14% of the frame width) |
| Ring Nebula (M57) | Fits, but small: about 35 px across |
| Jupiter | Fits, but small: about 19 px across |
Object sizes are approximate apparent sizes. Pixel counts use an image scale of 2.39″ per pixel. Try any combination in the field of view comparator.
Full specifications
| Aperture | 50 mm |
|---|---|
| Focal length | 250 mm (f/5) |
| Optics | 3-element apochromatic refractor (ED glass) |
| Sensor | Sony IMX462 · 2.1 MP |
| Field of view (telephoto) | 1.29° × 0.73° |
| Image scale | 2.39″ per pixel |
| Wide-angle camera | No |
| Weight | 2.5 kg |
| Battery | 6 h · 6,000 mAh |
| Storage | 64 GB |
| EQ mode | Yes (TC20 tripod recommended) |
| Filters | UV/IR-cut, duo-band (OIII 30 nm / Hα 20 nm), dark filter; magnetic solar filter included |
| Dew control | Built-in dew heater |
| Tripod included | Yes |
| Eyepiece | No |
| Collimation needed | No |
Official: 0.73° × 1.29° (portrait).
How it compares
Exposure length in alt-az mode
Alt-az tracking rotates the field slowly. With this field and image scale, the frame corner smears by one pixel after about 11 seconds (target due south at 45° altitude, observer at 40° latitude). That is why smart telescopes stack many short exposures; EQ mode removes the limit: Yes (TC20 tripod recommended). See EQ mode and wedges explained.
Comparisons
Other Seestar (ZWO) models
Frequently asked questions
How much does the Seestar S50 cost?
Listed at $499 but out of stock on seestar.com; the S50 Pro is its successor.
Can the Seestar S50 photograph the Andromeda Galaxy in one frame?
Needs a mosaic (about 3×2 frames). Its telephoto field is 1.29° × 0.73° and Andromeda spans about 3.2° × 1°.
Does the Seestar S50 have EQ mode?
Yes (TC20 tripod recommended).
Does the full Moon fit in the Seestar S50's field of view?
Yes. The Moon is about 0.52° across and the field is 1.29° × 0.73°.
Sources
Specs and prices checked on 11 Nov 2026.