Is the Seestar S50 faster than the Seestar S30 Pro?

From a Bortle 6 sky the Seestar S50 is 1.2× 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 Pro: which is faster for deep-sky imaging?

ZWO Seestar S50 against ZWO Seestar S30 Pro, 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 1.2× 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 Pro shows 3.99° × 2.24° 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 3.74″, 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 Pro
Aperture	50 mm	30 mm
Focal length	250 mm (f/5.0)	160 mm (f/5.3)
Sensor	Sony IMX462, 2.1 MP	Sony IMX585, 8.3 MP
Pixel size	2.9 µm	2.9 µm
Pixel scale	2.39″/px	3.74″/px
Field of view	1.28° × 0.72°	3.99° × 2.24°
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 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 Pro	Faster
Andromeda GalaxyGalaxy	1 h 27 min525 subs	1 h 41 min609 subs	Seestar S50 1.2×
Orion NebulaEmission nebula	12 min75 subs	15 min89 subs	Seestar S50 1.2×
North America NebulaEmission nebula	1 h 25 min512 subs	1 h 43 min619 subs	Seestar S50 1.2×
Pinwheel GalaxyGalaxy	4 h 37 min1,661 subs	5 h 21 min1,927 subs	Seestar S50 1.2×
Ring NebulaPlanetary nebula	7 min42 subs	8 min49 subs	Seestar S50 1.2×
Western Veil NebulaSupernova remnant	1 h 33 min557 subs	1 h 52 min674 subs	Seestar S50 1.2×
Hercules ClusterGlobular cluster	7 min44 subs	8 min51 subs	Seestar S50 1.2×
PleiadesReflection nebula	2 h 42 min971 subs	3 h 08 min1,127 subs	Seestar S50 1.2×

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 Pro	Faster
Andromeda GalaxyGalaxy	34 min204 subs	40 min243 subs	Seestar S50 1.2×
Orion NebulaEmission nebula	10 min58 subs	12 min70 subs	Seestar S50 1.2×
North America NebulaEmission nebula	59 min357 subs	1 h 14 min443 subs	Seestar S50 1.2×
Pinwheel GalaxyGalaxy	1 h 40 min602 subs	2 h722 subs	Seestar S50 1.2×
Ring NebulaPlanetary nebula	6 min36 subs	7 min42 subs	Seestar S50 1.2×
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 12 min433 subs	Seestar S50 1.2×

Try the Seestar S50 in the calculator Try the Seestar S30 Pro

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 Pro

The S30 optics upgraded to a quadruplet in front of an 8 MP IMX585. Same speed per pixel as the S30, four times the pixels, so you can crop hard.

Where to buy the Seestar S30 ProZWO 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 Pro page