Is the Seestar S50 Pro faster than the Vespera Pro?

From a Bortle 6 sky the Seestar S50 Pro is 2.5× faster on the 30 most popular deep-sky targets; from Bortle 3 the Seestar S50 Pro is 1.9× faster.

Which is better for small targets like planetary nebulae?

The Vespera Pro, with its finer pixel scale of 1.65″ per pixel.

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

ZWO Seestar S50 Pro against Vaonis Vespera Pro, 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 2.5× 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 1.9× faster.

Field of view. The Seestar S50 Pro shows 2.45° × 1.38° against 1.62° × 1.62°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Vespera Pro needs a mosaic or a tight crop.

Detail. The Vespera Pro samples at 1.65″ 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 Vespera Pro 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 Pro does not, which costs it heavily on emission nebulae from any suburban sky.

Specifications side by side

Spec	Seestar S50 Pro	Vespera Pro
Aperture	50 mm	50 mm
Focal length	260 mm (f/5.2)	250 mm (f/5.0)
Sensor	OmniVision OS08B10 (1/1.2″), 8.3 MP	Sony IMX676, 12.5 MP
Pixel size	2.9 µm	2 µm
Pixel scale	2.30″/px	1.65″/px
Field of view	2.45° × 1.38°	1.62° × 1.62°
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⁻	0.8 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 Pro	Faster
Andromeda GalaxyGalaxy	1 h 36 min575 subs	3 h 16 min1,176 subs	Seestar S50 Pro 2.0×
Orion NebulaEmission nebula	14 min83 subs	38 min227 subs	Seestar S50 Pro 2.7×
North America NebulaEmission nebula	1 h 36 min574 subs	5 h 04 min1,822 subs	Seestar S50 Pro 3×
Pinwheel GalaxyGalaxy	5 h 03 min1,817 subs	10 h3,727 subs	Seestar S50 Pro 2.1×
Ring NebulaPlanetary nebula	8 min46 subs	17 min103 subs	Seestar S50 Pro 2.3×
Western Veil NebulaSupernova remnant	1 h 44 min625 subs	5 h 32 min1,992 subs	Seestar S50 Pro 3×
Hercules ClusterGlobular cluster	8 min48 subs	16 min98 subs	Seestar S50 Pro 2.0×
PleiadesReflection nebula	2 h 57 min1,063 subs	6 h 03 min2,177 subs	Seestar S50 Pro 2.0×

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 Pro	Faster
Andromeda GalaxyGalaxy	38 min227 subs	1 h 23 min500 subs	Seestar S50 Pro 2.2×
Orion NebulaEmission nebula	11 min65 subs	18 min111 subs	Seestar S50 Pro 1.7×
North America NebulaEmission nebula	1 h 08 min407 subs	2 h 06 min757 subs	Seestar S50 Pro 1.9×
Pinwheel GalaxyGalaxy	1 h 52 min672 subs	4 h 10 min1,501 subs	Seestar S50 Pro 2.2×
Ring NebulaPlanetary nebula	7 min40 subs	10 min62 subs	Seestar S50 Pro 1.6×
Western Veil NebulaSupernova remnant	1 h 13 min441 subs	2 h 17 min824 subs	Seestar S50 Pro 1.9×
Hercules ClusterGlobular cluster	5 min30 subs	9 min53 subs	Seestar S50 Pro 1.7×
PleiadesReflection nebula	1 h 07 min404 subs	2 h 29 min897 subs	Seestar S50 Pro 2.2×

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

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 Pro

The square-sensor Vespera with 2 µm pixels. Higher resolution than the II, and correspondingly slower per pixel: expect around double the time for the same per-pixel SNR. Run-out in 2026 and replaced by the Vespera Pro 2.

Where to buy the Vespera ProAmazon UK Amazon USAffiliate 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 Pro page