Is the Seestar S50 faster than the Odyssey?

From a Bortle 6 sky the Seestar S50 is 5× faster on the 30 most popular deep-sky targets; from Bortle 3 the Seestar S50 is 6× faster.

Which is better for small targets like planetary nebulae?

The Odyssey, with its finer pixel scale of 0.93″ per pixel.

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

ZWO Seestar S50 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 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 is 6× faster.

Field of view. The Seestar S50 shows 1.28° × 0.72° 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 2.39″, 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 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 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

Spec	Seestar S50	Odyssey
Aperture	50 mm	85 mm
Focal length	250 mm (f/5.0)	320 mm (f/3.8)
Sensor	Sony IMX462, 2.1 MP	IMX415-class, 1.45 µm (Unistellar does not name it), 6.2 MP
Pixel size	2.9 µm	1.45 µm
Pixel scale	2.39″/px	0.93″/px
Field of view	1.28° × 0.72°	0.75° × 0.56°
Sub exposures	10 s, 20 s, 30 s, 60 s	4 s
Dual-band filter	Built in (LP filter)	None
“No filter” position	UV/IR-cut	No filter
Read noise used	1 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.
Target	Seestar S50	Odyssey	Faster
Andromeda GalaxyGalaxy	1 h 27 min525 subs	6 h 07 min5,505 subs	Seestar S50 4×
Orion NebulaEmission nebula	12 min75 subs	1 h 08 min1,016 subs	Seestar S50 5×
North America NebulaEmission nebula	1 h 25 min512 subs	9 h 33 min8,594 subs	Seestar S50 7×
Pinwheel GalaxyGalaxy	4 h 37 min1,661 subs	20 h17,741 subs	Seestar S50 4×
Ring NebulaPlanetary nebula	7 min42 subs	28 min422 subs	Seestar S50 4×
Western Veil NebulaSupernova remnant	1 h 33 min557 subs	10 h9,406 subs	Seestar S50 7×
Hercules ClusterGlobular cluster	7 min44 subs	28 min419 subs	Seestar S50 4×
PleiadesReflection nebula	2 h 42 min971 subs	11 h10,297 subs	Seestar S50 4×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
Target	Seestar S50	Odyssey	Faster
Andromeda GalaxyGalaxy	34 min204 subs	4 h 05 min3,683 subs	Seestar S50 7×
Orion NebulaEmission nebula	10 min58 subs	47 min701 subs	Seestar S50 5×
North America NebulaEmission nebula	59 min357 subs	6 h 21 min5,721 subs	Seestar S50 6×
Pinwheel GalaxyGalaxy	1 h 40 min602 subs	13 h11,739 subs	Seestar S50 8×
Ring NebulaPlanetary nebula	6 min36 subs	21 min309 subs	Seestar S50 3×
Western Veil NebulaSupernova remnant	1 h 04 min387 subs	6 h 57 min6,257 subs	Seestar S50 6×
Hercules ClusterGlobular cluster	5 min30 subs	20 min297 subs	Seestar S50 4×
PleiadesReflection nebula	1 h362 subs	7 h 36 min6,843 subs	Seestar S50 8×

Try the Seestar S50 in the calculator Try the Odyssey

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 Direct Amazon UK Amazon 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 UK Unistellar UK Amazon US Unistellar USAffiliate links: As an Amazon Associate I earn from qualifying purchases, at no cost to you.

Other comparisons

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