Seestar S50 Pro vs DWARF 3: which is faster for deep-sky imaging?

ZWO Seestar S50 Pro against DwarfLab DWARF 3, 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 Pro 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 Pro is 1.1× faster.

Field of view. The DWARF 3 shows 2.93° × 1.65° against 2.45° × 1.38°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Seestar S50 Pro needs a mosaic or a tight crop.

Detail. The Seestar S50 Pro samples at 2.30″ per pixel against 2.75″, 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 ProDWARF 3
Aperture50 mm35 mm
Focal length260 mm (f/5.2)150 mm (f/4.3)
SensorOmniVision OS08B10 (1/1.2″), 8.3 MPSony IMX678, 8.3 MP
Pixel size2.9 µm2 µm
Pixel scale2.30″/px2.75″/px
Field of view2.45° × 1.38°2.93° × 1.65°
Sub exposures10 s, 20 s, 30 s, 60 s15 s, 30 s, 60 s
Dual-band filterBuilt in (LP filter)Built in (Dual-band)
“No filter” positionUV/IR-cutAstro
Read noise used1 e⁻0.6 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 ProDWARF 3Faster
Andromeda GalaxyGalaxy1 h 36 min575 subs2 h 07 min509 subsSeestar S50 Pro 1.3×
Orion NebulaEmission nebula14 min83 subs16 min66 subsSeestar S50 Pro 1.2×
North America NebulaEmission nebula1 h 36 min574 subs1 h 46 min424 subsSeestar S50 Pro 1.1×
Pinwheel GalaxyGalaxy5 h 03 min1,817 subs6 h 41 min1,604 subsSeestar S50 Pro 1.3×
Ring NebulaPlanetary nebula8 min46 subs10 min39 subsSeestar S50 Pro 1.3×
Western Veil NebulaSupernova remnant1 h 44 min625 subs1 h 55 min460 subsSeestar S50 Pro 1.1×
Hercules ClusterGlobular cluster8 min48 subs11 min44 subsSeestar S50 Pro 1.3×
PleiadesReflection nebula2 h 57 min1,063 subs3 h 55 min939 subsSeestar S50 Pro 1.3×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
TargetSeestar S50 ProDWARF 3Faster
Andromeda GalaxyGalaxy38 min227 subs44 min178 subsSeestar S50 Pro 1.2×
Orion NebulaEmission nebula11 min65 subs12 min48 subsSeestar S50 Pro 1.1×
North America NebulaEmission nebula1 h 08 min407 subs1 h 06 min264 subsSame
Pinwheel GalaxyGalaxy1 h 52 min672 subs2 h 08 min514 subsSeestar S50 Pro 1.1×
Ring NebulaPlanetary nebula7 min40 subs8 min33 subsSeestar S50 Pro 1.2×
Western Veil NebulaSupernova remnant1 h 13 min441 subs1 h 11 min285 subsSame
Hercules ClusterGlobular cluster5 min30 subs8 min30 subsSeestar S50 Pro 1.5×
PleiadesReflection nebula1 h 07 min404 subs1 h 18 min312 subsSeestar S50 Pro 1.2×

Try the Seestar S50 Pro in the calculator Try the DWARF 3

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 DwarfLab DWARF 3

Small pixels on a 35 mm f/4.3 lens give a sharper image than its aperture suggests, and EQ mode with 60 s subs makes it the read-noise winner in dark skies.

Where to buy the DWARF 3DwarfLab 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 S50 Pro

DWARF 3

All comparisons · Buying guide · Seestar S50 Pro page · DWARF 3 page