Is the Seestar S50 Pro faster than the Vespera 3?

From a Bortle 6 sky the Seestar S50 Pro is 1.1× faster on the 30 most popular deep-sky targets; from Bortle 3 the Vespera 3 is 1.3× faster.

Which is better for small targets like planetary nebulae?

Neither has a meaningful advantage; their pixel scales are similar.

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

ZWO Seestar S50 Pro against Vaonis Vespera 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 1.1× faster (geometric mean of the solid-image times, each scope on its recommended filter and default subs). From a rural Bortle 3 sky the Vespera 3 is 1.3× faster, so the ranking flips under dark skies.

Field of view. The Vespera 3 shows 2.60° × 1.46° 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. Pixel scales are within 10% of each other, so neither has a real detail advantage.

Subs and dark skies. The Seestar S50 Pro goes up to 60 s subs in EQ mode, the Vespera 3 tops out at 30 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 Vespera 3 does not, which costs it heavily on emission nebulae from any suburban sky.

Specifications side by side

Spec	Seestar S50 Pro	Vespera 3
Aperture	50 mm	50 mm
Focal length	260 mm (f/5.2)	245 mm (f/4.9)
Sensor	OmniVision OS08B10 (1/1.2″), 8.3 MP	Sony IMX585, 8.3 MP
Pixel size	2.9 µm	2.9 µm
Pixel scale	2.30″/px	2.44″/px
Field of view	2.45° × 1.38°	2.60° × 1.46°
Sub exposures	10 s, 20 s, 30 s, 60 s	10 s, 20 s, 30 s
Dual-band filter	Built in (LP filter)	Clip-on option (Dual Band filter)
“No filter” position	UV/IR-cut	No filter
Read noise used	1 e⁻	1 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 Pro	Vespera 3	Faster
Andromeda GalaxyGalaxy	1 h 36 min575 subs	1 h 24 min502 subs	Vespera 3 1.1×
Orion NebulaEmission nebula	14 min83 subs	16 min98 subs	Seestar S50 Pro 1.2×
North America NebulaEmission nebula	1 h 36 min574 subs	2 h 09 min777 subs	Seestar S50 Pro 1.4×
Pinwheel GalaxyGalaxy	5 h 03 min1,817 subs	4 h 24 min1,586 subs	Vespera 3 1.1×
Ring NebulaPlanetary nebula	8 min46 subs	7 min45 subs	Same
Western Veil NebulaSupernova remnant	1 h 44 min625 subs	2 h 21 min849 subs	Seestar S50 Pro 1.4×
Hercules ClusterGlobular cluster	8 min48 subs	7 min43 subs	Vespera 3 1.1×
PleiadesReflection nebula	2 h 57 min1,063 subs	2 h 35 min928 subs	Vespera 3 1.1×

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 Pro	Vespera 3	Faster
Andromeda GalaxyGalaxy	38 min227 subs	32 min193 subs	Vespera 3 1.2×
Orion NebulaEmission nebula	11 min65 subs	7 min45 subs	Vespera 3 1.5×
North America NebulaEmission nebula	1 h 08 min407 subs	48 min290 subs	Vespera 3 1.4×
Pinwheel GalaxyGalaxy	1 h 52 min672 subs	1 h 35 min569 subs	Vespera 3 1.2×
Ring NebulaPlanetary nebula	7 min40 subs	5 min30 subs	Vespera 3 1.3×
Western Veil NebulaSupernova remnant	1 h 13 min441 subs	52 min315 subs	Vespera 3 1.4×
Hercules ClusterGlobular cluster	5 min30 subs	5 min30 subs	Same
PleiadesReflection nebula	1 h 07 min404 subs	57 min343 subs	Vespera 3 1.2×

Try the Seestar S50 Pro in the calculator Try the Vespera 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 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 Vaonis Vespera 3

The 2026 Vespera: same 50 mm quadruplet class as the II on an 8 MP IMX585, with a 24 MP mosaic mode and 11 hours of battery. Per pixel it behaves like a Seestar S50 Pro without the built-in dual-band filter.

Where to buy the Vespera 3Vaonis store Direct Amazon UK Amazon USThe Vaonis 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

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