How Many Subs

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

ZWO Seestar S30 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 S30 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 they are about the same speed.

Field of view. The Seestar S30 Pro shows 3.99° × 2.24° 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. Pixel scales are within 10% of each other, so neither has a real detail advantage.

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 S30Seestar S30 Pro
Aperture30 mm30 mm
Focal length150 mm (f/5.0)160 mm (f/5.3)
SensorSony IMX662, 2.1 MPSony IMX585, 8.3 MP
Pixel size2.9 µm2.9 µm
Pixel scale3.99″/px3.74″/px
Field of view2.13° × 1.20°3.99° × 2.24°
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 used1.2 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.
TargetSeestar S30Seestar S30 ProFaster
Andromeda GalaxyGalaxy1 h 32 min552 subs1 h 41 min609 subsSeestar S30 1.1×
Orion NebulaEmission nebula14 min84 subs15 min89 subsSeestar S30 1.1×
North America NebulaEmission nebula1 h 39 min597 subs1 h 43 min619 subsSame
Pinwheel GalaxyGalaxy4 h 51 min1,748 subs5 h 21 min1,927 subsSeestar S30 1.1×
Ring NebulaPlanetary nebula7 min45 subs8 min49 subsSeestar S30 1.1×
Western Veil NebulaSupernova remnant1 h 48 min651 subs1 h 52 min674 subsSame
Hercules ClusterGlobular cluster8 min46 subs8 min51 subsSeestar S30 1.1×
PleiadesReflection nebula2 h 50 min1,022 subs3 h 08 min1,127 subsSeestar S30 1.1×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
TargetSeestar S30Seestar S30 ProFaster
Andromeda GalaxyGalaxy38 min231 subs40 min243 subsSeestar S30 1.1×
Orion NebulaEmission nebula11 min67 subs12 min70 subsSame
North America NebulaEmission nebula1 h 14 min442 subs1 h 14 min443 subsSame
Pinwheel GalaxyGalaxy1 h 55 min689 subs2 h722 subsSame
Ring NebulaPlanetary nebula6 min39 subs7 min42 subsSeestar S30 1.1×
Western Veil NebulaSupernova remnant1 h 20 min481 subs1 h 20 min481 subsSame
Hercules ClusterGlobular cluster5 min30 subs5 min30 subsSame
PleiadesReflection nebula1 h 09 min412 subs1 h 12 min433 subsSeestar S30 1.1×

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

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.

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 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 S30

Seestar S30 Pro

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