How Many Subs

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

ZWO Seestar S30 against DwarfLab DWARF mini, 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 DWARF mini 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 DWARF mini is 1.1× faster.

Field of view. Both frame 2.1° or so on the long side, so they suit the same targets.

Detail. Pixel scales are within 10% of each other, so neither has a real detail advantage.

Subs and dark skies. The DWARF mini goes up to 90 s subs in EQ mode, the Seestar S30 tops out at 60 s. That matters little from a city, where skyglow sets the floor, and a lot from a dark site, where read noise does.

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

Specifications side by side

SpecSeestar S30DWARF mini
Aperture30 mm30 mm
Focal length150 mm (f/5.0)150 mm (f/5.0)
SensorSony IMX662, 2.1 MPSony IMX662, 2.1 MP
Pixel size2.9 µm2.9 µm
Pixel scale3.99″/px3.99″/px
Field of view2.13° × 1.20°2.13° × 1.20°
Sub exposures10 s, 20 s, 30 s, 60 s15 s, 30 s, 60 s, 90 s
Dual-band filterBuilt in (LP filter)Built in (Dual-band)
“No filter” positionUV/IR-cutAstro
Read noise used1.2 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 S30DWARF miniFaster
Andromeda GalaxyGalaxy1 h 32 min552 subs1 h 27 min349 subsDWARF mini 1.1×
Orion NebulaEmission nebula14 min84 subs12 min50 subsDWARF mini 1.1×
North America NebulaEmission nebula1 h 39 min597 subs1 h 24 min336 subsDWARF mini 1.2×
Pinwheel GalaxyGalaxy4 h 51 min1,748 subs4 h 35 min1,102 subsDWARF mini 1.1×
Ring NebulaPlanetary nebula7 min45 subs8 min30 subsSame
Western Veil NebulaSupernova remnant1 h 48 min651 subs1 h 31 min366 subsDWARF mini 1.2×
Hercules ClusterGlobular cluster8 min46 subs8 min30 subsSame
PleiadesReflection nebula2 h 50 min1,022 subs2 h 41 min645 subsDWARF mini 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 S30DWARF miniFaster
Andromeda GalaxyGalaxy38 min231 subs34 min135 subsDWARF mini 1.1×
Orion NebulaEmission nebula11 min67 subs9 min38 subsDWARF mini 1.2×
North America NebulaEmission nebula1 h 14 min442 subs58 min233 subsDWARF mini 1.3×
Pinwheel GalaxyGalaxy1 h 55 min689 subs1 h 39 min396 subsDWARF mini 1.2×
Ring NebulaPlanetary nebula6 min39 subs8 min30 subsSeestar S30 1.2×
Western Veil NebulaSupernova remnant1 h 20 min481 subs1 h 03 min253 subsDWARF mini 1.3×
Hercules ClusterGlobular cluster5 min30 subs8 min30 subsSeestar S30 1.5×
PleiadesReflection nebula1 h 09 min412 subs1 h239 subsDWARF mini 1.2×

Try the Seestar S30 in the calculator Try the DWARF mini

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 DwarfLab DWARF mini

DwarfLab’s answer to the Seestar S30: same sensor and focal length, big pixels, dual-band filter built in, and 90 s subs in EQ mode. Sensitivity over megapixels.

Where to buy the DWARF miniDwarfLab store UKDwarfLab store USAmazon UKAmazon USThe DwarfLab 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

DWARF mini

All comparisons · Buying guide · Seestar S30 page · DWARF mini page