Both telescopes start working out of the box, both produce surprisingly good deep-sky images for the price, and both have growing communities. But they’re not equivalent. The right choice depends on what you want to image and where you image from.
Quick takeaways
If you live somewhere with consistently dark skies and want to shoot galaxies and globular clusters, the Dwarf 3 has the slight edge — its EQ Mode lets you take longer subs without trailing, which matters for faint targets.
If you live in a light-polluted suburb and want to shoot emission nebulae that respond well to narrowband filtering, the Seestar S50 can take an external Duo-Band filter that works better than the Dwarf 3’s built-in equivalent in some cases.
If you’re not sure, this article is for you.
Specifications side by side
| Dwarf 3 | Seestar S50 | |
|---|---|---|
| Aperture | 35 mm | 50 mm |
| Focal length | 150 mm | 250 mm |
| f/ratio | f/4.3 | f/5 |
| Sensor | Sony IMX678 | Sony IMX462 |
| Built-in filters | VIS / Astro / Duo-Band | None (external only) |
| EQ Mode | Yes | No (alt-az only) |
| Max sub length (typical) | 30 s with EQ | 10 s |
| App | DwarfLab (iOS / Android) | ZWO Seesharp (iOS / Android) |
| Battery | Internal, ~6 h | Internal, ~6 h |
| Approx price (mid-2026) | €499 | €499 |
The aperture difference is the headline number, but it’s misleading on its own. A 50 mm aperture at f/5 collects more total light than a 35 mm at f/4.3, but the Dwarf 3’s faster f-ratio means each sub is more efficient per second. Over an hour of integration the gap closes.
The sub-length difference is the bigger deal. EQ Mode on the Dwarf 3 lets you take 30-second exposures of deep-sky targets without trailing, which means fewer subs to stack and less read-noise to fight. The Seestar S50 caps out at around 10 seconds in alt-az mode.
Where the Dwarf 3 wins
- EQ Mode for galaxies and globulars. M31, M81, M51, M13 — anything dim and detailed benefits from the longer subs the Dwarf 3 enables. This is the single biggest practical difference.
- Built-in Duo-Band filter. No accessories to buy. Pull it up in the app, frame the target, hit go.
- Built-in wide-angle lens. A second optical path for Milky Way and constellation work without changing telescopes.
Where the Seestar S50 wins
- Bigger aperture. Brighter base image. For solar-system work — Moon, Jupiter, Saturn — the S50 just shows more.
- External filter freedom. The S50 takes 1.25” filters in the optical path, so you can swap in a high-end Astronomik or Optolong narrowband filter that exceeds what’s built into the Dwarf 3.
- Mature app ecosystem. ZWO has been making astro gear for years. The Seesharp app is more polished and has more community support.
What doesn’t matter as much as you’d think
- Resolution numbers. Both telescopes are limited by atmospheric seeing well before pixel count. A 1080p sensor with sharp optics beats a 4K sensor with muddy ones.
- Battery life. Both will run a full session. Bring a USB-C power bank either way.
- Brand. This is hobbyist gear, not life-support equipment. Buy what fits your sky, not what has more YouTube reviews.
My recommendation
For most beginners in light-polluted Europe or the UK, the Dwarf 3 is the safer first telescope. EQ Mode means more keeper frames per session under realistic conditions, and the built-in filter wheel removes the “what filter do I buy first” decision that stalls a lot of new owners.
For someone with darker skies, an existing filter collection, or a bias towards solar-system imaging, the Seestar S50 is the better fit — bigger aperture, more flexibility downstream.
If you can borrow either before buying, do it. There’s no substitute for ten minutes of using a thing.
This is a comparison piece, not a buyer’s guide tied to current pricing. If you’re ready to buy, head to the Suppliers page — and yes, those are affiliate links, which is documented in the Affiliate disclosure. The price you pay is the same either way.