Is the Seestar S50 faster than the Seestar S30?

From a Bortle 6 sky the Seestar S50 is 1.1× faster on the 30 most popular deep-sky targets; from Bortle 3 the Seestar S50 is 1.2× faster.

Which is better for small targets like planetary nebulae?

The Seestar S50, with its finer pixel scale of 2.39″ per pixel.

Seestar S50 vs Seestar S30: which is faster for deep-sky imaging?

ZWO Seestar S50 against ZWO Seestar S30, on the same targets from the same skies, using the same photon-budget model as the rest of the site. Times are for a solid image; the calculator gives quick-look and showpiece figures too.

Speed. Across the 30 most popular targets from a suburban Bortle 6 sky, the Seestar S50 is 1.1× faster (geometric mean of the solid-image times, each scope on its recommended filter and default subs). From a rural Bortle 3 sky the Seestar S50 is 1.2× faster.

Field of view. The Seestar S30 shows 2.13° × 1.20° against 1.28° × 0.72°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Seestar S50 needs a mosaic or a tight crop.

Detail. The Seestar S50 samples at 2.39″ per pixel against 3.99″, so it pulls finer structure from small targets: planetary nebulae, globular cores, galaxy arms.

Subs and dark skies. Both top out at 60 s subs, so neither has an edge at read-noise-limited dark sites.

Filters. Both carry a dual-band filter, which is what makes emission nebulae practical from a lit sky.

Specifications side by side

Spec	Seestar S50	Seestar S30
Aperture	50 mm	30 mm
Focal length	250 mm (f/5.0)	150 mm (f/5.0)
Sensor	Sony IMX462, 2.1 MP	Sony IMX662, 2.1 MP
Pixel size	2.9 µm	2.9 µm
Pixel scale	2.39″/px	3.99″/px
Field of view	1.28° × 0.72°	2.13° × 1.20°
Sub exposures	10 s, 20 s, 30 s, 60 s	10 s, 20 s, 30 s, 60 s
Dual-band filter	Built in (LP filter)	Built in (LP filter)
“No filter” position	UV/IR-cut	UV/IR-cut
Read noise used	1 e⁻	1.2 e⁻

Timed on the same targets

Suburban sky (Bortle 6)

Total integration for a solid image from a Bortle 6 sky, default subs, recommended filter for each scope.
Target	Seestar S50	Seestar S30	Faster
Andromeda GalaxyGalaxy	1 h 27 min525 subs	1 h 32 min552 subs	Seestar S50 1.1×
Orion NebulaEmission nebula	12 min75 subs	14 min84 subs	Seestar S50 1.1×
North America NebulaEmission nebula	1 h 25 min512 subs	1 h 39 min597 subs	Seestar S50 1.2×
Pinwheel GalaxyGalaxy	4 h 37 min1,661 subs	4 h 51 min1,748 subs	Seestar S50 1.1×
Ring NebulaPlanetary nebula	7 min42 subs	7 min45 subs	Seestar S50 1.1×
Western Veil NebulaSupernova remnant	1 h 33 min557 subs	1 h 48 min651 subs	Seestar S50 1.2×
Hercules ClusterGlobular cluster	7 min44 subs	8 min46 subs	Same
PleiadesReflection nebula	2 h 42 min971 subs	2 h 50 min1,022 subs	Seestar S50 1.1×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
Target	Seestar S50	Seestar S30	Faster
Andromeda GalaxyGalaxy	34 min204 subs	38 min231 subs	Seestar S50 1.1×
Orion NebulaEmission nebula	10 min58 subs	11 min67 subs	Seestar S50 1.2×
North America NebulaEmission nebula	59 min357 subs	1 h 14 min442 subs	Seestar S50 1.2×
Pinwheel GalaxyGalaxy	1 h 40 min602 subs	1 h 55 min689 subs	Seestar S50 1.1×
Ring NebulaPlanetary nebula	6 min36 subs	6 min39 subs	Seestar S50 1.1×
Western Veil NebulaSupernova remnant	1 h 04 min387 subs	1 h 20 min481 subs	Seestar S50 1.2×
Hercules ClusterGlobular cluster	5 min30 subs	5 min30 subs	Same
PleiadesReflection nebula	1 h362 subs	1 h 09 min412 subs	Seestar S50 1.1×

Try the Seestar S50 in the calculator Try the Seestar S30

About the ZWO Seestar S50

The scope that made smart astrophotography mainstream. 50 mm triplet, 2 MP sensor, dual-band filter on a wheel. Alt-Az stacking at 10 s, EQ mode unlocks 60 s. Out of production since 2026 and replaced by the S50 Pro, but there are a great many in use.

Where to buy the Seestar S50ZWO store Direct Amazon UK Amazon USThe ZWO store link is a plain link; the others are affiliate links. As an Amazon Associate I earn from qualifying purchases, at no cost to you.

About the ZWO Seestar S30

Wider and lighter than the S50 with the same 2.9 µm pixels, so its per-pixel speed on extended targets is close despite the smaller aperture. Ideal for big nebulae.

Where to buy the Seestar S30ZWO store Direct Amazon UK Amazon USThe ZWO store link is a plain link; the others are affiliate links. As an Amazon Associate I earn from qualifying purchases, at no cost to you.

Other comparisons

All comparisons · Buying guide · Seestar S50 page · Seestar S30 page