Seestar S30 vs Vespera II: which is faster for deep-sky imaging?

ZWO Seestar S30 against Vaonis Vespera II, 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 S30 is 1.2× 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 II is 1.3× faster, so the ranking flips under dark skies.

Field of view. The Vespera II shows 2.55° × 1.44° against 2.13° × 1.20°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Seestar S30 needs a mosaic or a tight crop.

Detail. The Vespera II samples at 2.39″ per pixel against 3.99″, so it pulls finer structure from small targets: planetary nebulae, globular cores, galaxy arms.

Subs and dark skies. The Seestar S30 goes up to 60 s subs in EQ mode, the Vespera II 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 S30 has a dual-band filter built in; the Vespera II does not, which costs it heavily on emission nebulae from any suburban sky.

Specifications side by side

Timed on the same targets

Suburban sky (Bortle 6)

Rural sky (Bortle 3)

Try the Seestar S30 in the calculator Try the Vespera II

About the ZWO Seestar S30

Wider and lighter than the S50 with the same 2.9 µm pixels, so its per-pixel speed on extended targets is close despite the smaller aperture. Ideal for big nebulae.

About the Vaonis Vespera II

A 50 mm quadruplet on an 8 MP sensor with Vaonis’s mosaic mode for wide fields. Same optics class as the Seestar S50, four times the pixels.

Other comparisons

All comparisons · Buying guide · Seestar S30 page · Vespera II page