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

ZWO Seestar S50 against DwarfLab DWARF II, 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 4× 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 4× faster.

Field of view. The DWARF II shows 3.19° × 1.79° 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 2.99″, so it pulls finer structure from small targets: planetary nebulae, globular cores, galaxy arms.

Subs and dark skies. The Seestar S50 goes up to 60 s subs in EQ mode, the DWARF II tops out at 15 s. That matters little from a city, where skyglow sets the floor, and a lot from a dark site, where read noise does.

Filters. The Seestar S50 has a dual-band filter built in; the DWARF II does not, which costs it heavily on emission nebulae from any suburban sky.

Specifications side by side

SpecSeestar S50DWARF II
Aperture50 mm24 mm
Focal length250 mm (f/5.0)100 mm (f/4.2)
SensorSony IMX462, 2.1 MPSony IMX415, 8.3 MP
Pixel size2.9 µm1.45 µm
Pixel scale2.39″/px2.99″/px
Field of view1.28° × 0.72°3.19° × 1.79°
Sub exposures10 s, 20 s, 30 s, 60 s15 s
Dual-band filterBuilt in (LP filter)None
“No filter” positionUV/IR-cutAstro
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 S50DWARF IIFaster
Andromeda GalaxyGalaxy1 h 27 min525 subs4 h 59 min1,198 subsSeestar S50 3×
Orion NebulaEmission nebula12 min75 subs57 min228 subsSeestar S50 5×
North America NebulaEmission nebula1 h 25 min512 subs7 h 45 min1,860 subsSeestar S50 5×
Pinwheel GalaxyGalaxy4 h 37 min1,661 subs16 h3,817 subsSeestar S50 3×
Ring NebulaPlanetary nebula7 min42 subs25 min101 subsSeestar S50 4×
Western Veil NebulaSupernova remnant1 h 33 min557 subs8 h 29 min2,035 subsSeestar S50 5×
Hercules ClusterGlobular cluster7 min44 subs24 min97 subsSeestar S50 3×
PleiadesReflection nebula2 h 42 min971 subs9 h 16 min2,225 subsSeestar S50 3×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
TargetSeestar S50DWARF IIFaster
Andromeda GalaxyGalaxy34 min204 subs2 h 31 min603 subsSeestar S50 4×
Orion NebulaEmission nebula10 min58 subs31 min126 subsSeestar S50 3×
North America NebulaEmission nebula59 min357 subs3 h 50 min922 subsSeestar S50 4×
Pinwheel GalaxyGalaxy1 h 40 min602 subs7 h 44 min1,856 subsSeestar S50 5×
Ring NebulaPlanetary nebula6 min36 subs16 min64 subsSeestar S50 2.7×
Western Veil NebulaSupernova remnant1 h 04 min387 subs4 h 11 min1,006 subsSeestar S50 4×
Hercules ClusterGlobular cluster5 min30 subs14 min57 subsSeestar S50 2.8×
PleiadesReflection nebula1 h362 subs4 h 34 min1,097 subsSeestar S50 5×

Try the Seestar S50 in the calculator Try the DWARF II

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 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 II

The original pocket scope. 24 mm aperture and tiny 1.45 µm pixels mean it is slow per pixel, so bin or downsample and be patient.

Where to buy the DWARF IIAmazon UKAmazon USAffiliate links: As an Amazon Associate I earn from qualifying purchases, at no cost to you.

Other comparisons

Seestar S50

DWARF II

All comparisons · Buying guide · Seestar S50 page · DWARF II page