How Many Subs

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

ZWO Seestar S50 Pro against Unistellar Odyssey, 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 5× 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 5× faster.

Field of view. The Seestar S50 Pro shows 2.45° × 1.38° against 0.75° × 0.56°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Odyssey needs a mosaic or a tight crop.

Detail. The Odyssey samples at 0.93″ per pixel against 2.30″, so it pulls finer structure from small targets: planetary nebulae, globular cores, galaxy arms.

Subs and dark skies. The Seestar S50 Pro goes up to 60 s subs in EQ mode, the Odyssey tops out at 4 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 Pro has a dual-band filter built in; the Odyssey does not, which costs it heavily on emission nebulae from any suburban sky.

Specifications side by side

SpecSeestar S50 ProOdyssey
Aperture50 mm85 mm
Focal length260 mm (f/5.2)320 mm (f/3.8)
SensorOmniVision OS08B10 (1/1.2″), 8.3 MPIMX415-class, 1.45 µm (Unistellar does not name it), 6.2 MP
Pixel size2.9 µm1.45 µm
Pixel scale2.30″/px0.93″/px
Field of view2.45° × 1.38°0.75° × 0.56°
Sub exposures10 s, 20 s, 30 s, 60 s4 s
Dual-band filterBuilt in (LP filter)None
“No filter” positionUV/IR-cutNo filter
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 ProOdysseyFaster
Andromeda GalaxyGalaxy1 h 36 min575 subs6 h 07 min5,505 subsSeestar S50 Pro 4×
Orion NebulaEmission nebula14 min83 subs1 h 08 min1,016 subsSeestar S50 Pro 5×
North America NebulaEmission nebula1 h 36 min574 subs9 h 33 min8,594 subsSeestar S50 Pro 6×
Pinwheel GalaxyGalaxy5 h 03 min1,817 subs20 h17,741 subsSeestar S50 Pro 4×
Ring NebulaPlanetary nebula8 min46 subs28 min422 subsSeestar S50 Pro 4×
Western Veil NebulaSupernova remnant1 h 44 min625 subs10 h9,406 subsSeestar S50 Pro 6×
Hercules ClusterGlobular cluster8 min48 subs28 min419 subsSeestar S50 Pro 3×
PleiadesReflection nebula2 h 57 min1,063 subs11 h10,297 subsSeestar S50 Pro 4×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
TargetSeestar S50 ProOdysseyFaster
Andromeda GalaxyGalaxy38 min227 subs4 h 05 min3,683 subsSeestar S50 Pro 7×
Orion NebulaEmission nebula11 min65 subs47 min701 subsSeestar S50 Pro 4×
North America NebulaEmission nebula1 h 08 min407 subs6 h 21 min5,721 subsSeestar S50 Pro 6×
Pinwheel GalaxyGalaxy1 h 52 min672 subs13 h11,739 subsSeestar S50 Pro 7×
Ring NebulaPlanetary nebula7 min40 subs21 min309 subsSeestar S50 Pro 3×
Western Veil NebulaSupernova remnant1 h 13 min441 subs6 h 57 min6,257 subsSeestar S50 Pro 6×
Hercules ClusterGlobular cluster5 min30 subs20 min297 subsSeestar S50 Pro 4×
PleiadesReflection nebula1 h 07 min404 subs7 h 36 min6,843 subsSeestar S50 Pro 7×

Try the Seestar S50 Pro in the calculator Try the Odyssey

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 Unistellar Odyssey

Unistellar’s compact 85 mm with autofocus and tiny pixels. Sharp, but the fine sampling costs time on faint extended targets. The Odyssey Pro is the same telescope with an eyepiece added, so these figures apply to both.

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

Other comparisons

Seestar S50 Pro

Odyssey

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