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

ZWO Seestar S50 Pro 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, they are about the same speed. From a rural Bortle 3 sky they are about the same speed.

Field of view. The Seestar S50 Pro shows 2.45° × 1.38° against 2.13° × 1.20°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Seestar S30 needs a mosaic or a tight crop.

Detail. The Seestar S50 Pro samples at 2.30″ 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

SpecSeestar S50 ProSeestar S30
Aperture50 mm30 mm
Focal length260 mm (f/5.2)150 mm (f/5.0)
SensorOmniVision OS08B10 (1/1.2″), 8.3 MPSony IMX662, 2.1 MP
Pixel size2.9 µm2.9 µm
Pixel scale2.30″/px3.99″/px
Field of view2.45° × 1.38°2.13° × 1.20°
Sub exposures10 s, 20 s, 30 s, 60 s10 s, 20 s, 30 s, 60 s
Dual-band filterBuilt in (LP filter)Built in (LP filter)
“No filter” positionUV/IR-cutUV/IR-cut
Read noise used1 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.
TargetSeestar S50 ProSeestar S30Faster
Andromeda GalaxyGalaxy1 h 36 min575 subs1 h 32 min552 subsSame
Orion NebulaEmission nebula14 min83 subs14 min84 subsSame
North America NebulaEmission nebula1 h 36 min574 subs1 h 39 min597 subsSame
Pinwheel GalaxyGalaxy5 h 03 min1,817 subs4 h 51 min1,748 subsSame
Ring NebulaPlanetary nebula8 min46 subs7 min45 subsSame
Western Veil NebulaSupernova remnant1 h 44 min625 subs1 h 48 min651 subsSame
Hercules ClusterGlobular cluster8 min48 subs8 min46 subsSame
PleiadesReflection nebula2 h 57 min1,063 subs2 h 50 min1,022 subsSame

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
TargetSeestar S50 ProSeestar S30Faster
Andromeda GalaxyGalaxy38 min227 subs38 min231 subsSame
Orion NebulaEmission nebula11 min65 subs11 min67 subsSame
North America NebulaEmission nebula1 h 08 min407 subs1 h 14 min442 subsSeestar S50 Pro 1.1×
Pinwheel GalaxyGalaxy1 h 52 min672 subs1 h 55 min689 subsSame
Ring NebulaPlanetary nebula7 min40 subs6 min39 subsSame
Western Veil NebulaSupernova remnant1 h 13 min441 subs1 h 20 min481 subsSeestar S50 Pro 1.1×
Hercules ClusterGlobular cluster5 min30 subs5 min30 subsSame
PleiadesReflection nebula1 h 07 min404 subs1 h 09 min412 subsSame

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

About the ZWO Seestar S50 Pro

The S50 optics at 260 mm on an 8 MP 1/1.2-inch sensor: a wider, taller field, four times the pixels, and 60 s subs in EQ mode. Per pixel it is a whisker slower than the S50 because of the longer focal length; the long subs make it the better dark-site scope.

Where to buy the Seestar S50 ProZWO store DirectAmazon UKAmazon 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 DirectAmazon UKAmazon 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

Seestar S50 Pro

Seestar S30

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