Is the Seestar S50 faster than the Vespera Pro?

From a Bortle 6 sky the Seestar S50 is 2.8× faster on the 30 most popular deep-sky targets; from Bortle 3 the Seestar S50 is 2.1× 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 vs Vespera Pro: which is faster for deep-sky imaging?

ZWO Seestar S50 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 is 2.8× 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 2.1× faster.

Field of view. The Vespera Pro shows 1.62° × 1.62° against 1.28° × 0.72°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Seestar S50 needs a mosaic or a tight crop.

Detail. The Vespera Pro samples at 1.65″ 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 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 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	Vespera Pro
Aperture	50 mm	50 mm
Focal length	250 mm (f/5.0)	250 mm (f/5.0)
Sensor	Sony IMX462, 2.1 MP	Sony IMX676, 12.5 MP
Pixel size	2.9 µm	2 µm
Pixel scale	2.39″/px	1.65″/px
Field of view	1.28° × 0.72°	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	Vespera Pro	Faster
Andromeda GalaxyGalaxy	1 h 27 min525 subs	3 h 16 min1,176 subs	Seestar S50 2.2×
Orion NebulaEmission nebula	12 min75 subs	38 min227 subs	Seestar S50 3×
North America NebulaEmission nebula	1 h 25 min512 subs	5 h 04 min1,822 subs	Seestar S50 4×
Pinwheel GalaxyGalaxy	4 h 37 min1,661 subs	10 h3,727 subs	Seestar S50 2.2×
Ring NebulaPlanetary nebula	7 min42 subs	17 min103 subs	Seestar S50 2.5×
Western Veil NebulaSupernova remnant	1 h 33 min557 subs	5 h 32 min1,992 subs	Seestar S50 4×
Hercules ClusterGlobular cluster	7 min44 subs	16 min98 subs	Seestar S50 2.2×
PleiadesReflection nebula	2 h 42 min971 subs	6 h 03 min2,177 subs	Seestar S50 2.2×

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	Vespera Pro	Faster
Andromeda GalaxyGalaxy	34 min204 subs	1 h 23 min500 subs	Seestar S50 2.5×
Orion NebulaEmission nebula	10 min58 subs	18 min111 subs	Seestar S50 1.9×
North America NebulaEmission nebula	59 min357 subs	2 h 06 min757 subs	Seestar S50 2.1×
Pinwheel GalaxyGalaxy	1 h 40 min602 subs	4 h 10 min1,501 subs	Seestar S50 2.5×
Ring NebulaPlanetary nebula	6 min36 subs	10 min62 subs	Seestar S50 1.7×
Western Veil NebulaSupernova remnant	1 h 04 min387 subs	2 h 17 min824 subs	Seestar S50 2.1×
Hercules ClusterGlobular cluster	5 min30 subs	9 min53 subs	Seestar S50 1.7×
PleiadesReflection nebula	1 h362 subs	2 h 29 min897 subs	Seestar S50 2.5×

Try the Seestar S50 in the calculator Try the Vespera Pro

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 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 page · Vespera Pro page