Is the Seestar S50 faster than the Vespera Pro 2?

From a Bortle 6 sky the Seestar S50 is 2.7× faster on the 30 most popular deep-sky targets; from Bortle 3 the Seestar S50 is 2.0× faster.

Which is better for small targets like planetary nebulae?

The Vespera Pro 2, with its finer pixel scale of 1.68″ per pixel.

Seestar S50 vs Vespera Pro 2: which is faster for deep-sky imaging?

ZWO Seestar S50 against Vaonis Vespera Pro 2, 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 2.7× 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 2.0× faster.

Field of view. The Vespera Pro 2 shows 1.65° × 1.65° 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 2 samples at 1.68″ 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 2 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 2 does not, which costs it heavily on emission nebulae from any suburban sky.

Specifications side by side

Spec	Seestar S50	Vespera Pro 2
Aperture	50 mm	50 mm
Focal length	250 mm (f/5.0)	245 mm (f/4.9)
Sensor	Sony IMX462, 2.1 MP	Sony IMX676, 12.5 MP
Pixel size	2.9 µm	2 µm
Pixel scale	2.39″/px	1.68″/px
Field of view	1.28° × 0.72°	1.65° × 1.65°
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 2	Faster
Andromeda GalaxyGalaxy	1 h 27 min525 subs	3 h 07 min1,121 subs	Seestar S50 2.1×
Orion NebulaEmission nebula	12 min75 subs	36 min217 subs	Seestar S50 2.9×
North America NebulaEmission nebula	1 h 25 min512 subs	4 h 49 min1,736 subs	Seestar S50 3×
Pinwheel GalaxyGalaxy	4 h 37 min1,661 subs	9 h 52 min3,552 subs	Seestar S50 2.1×
Ring NebulaPlanetary nebula	7 min42 subs	16 min99 subs	Seestar S50 2.4×
Western Veil NebulaSupernova remnant	1 h 33 min557 subs	5 h 16 min1,898 subs	Seestar S50 3×
Hercules ClusterGlobular cluster	7 min44 subs	15 min93 subs	Seestar S50 2.1×
PleiadesReflection nebula	2 h 42 min971 subs	5 h 46 min2,075 subs	Seestar S50 2.1×

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	Vespera Pro 2	Faster
Andromeda GalaxyGalaxy	34 min204 subs	1 h 19 min472 subs	Seestar S50 2.3×
Orion NebulaEmission nebula	10 min58 subs	17 min105 subs	Seestar S50 1.8×
North America NebulaEmission nebula	59 min357 subs	1 h 59 min713 subs	Seestar S50 2.0×
Pinwheel GalaxyGalaxy	1 h 40 min602 subs	3 h 56 min1,414 subs	Seestar S50 2.3×
Ring NebulaPlanetary nebula	6 min36 subs	10 min59 subs	Seestar S50 1.6×
Western Veil NebulaSupernova remnant	1 h 04 min387 subs	2 h 09 min776 subs	Seestar S50 2.0×
Hercules ClusterGlobular cluster	5 min30 subs	8 min50 subs	Seestar S50 1.6×
PleiadesReflection nebula	1 h362 subs	2 h 21 min845 subs	Seestar S50 2.3×

Try the Seestar S50 in the calculator Try the Vespera Pro 2

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 2

The square-sensor 2026 Vespera with 2 µm pixels. Sharper than the Vespera 3 on small targets and correspondingly slower per pixel; the 12.5 MP square frame suits galaxies and planetaries.

Where to buy the Vespera Pro 2Vaonis 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 page · Vespera Pro 2 page