How Many Subs

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

DwarfLab DWARF II 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 Vespera II is 3× 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 4× faster.

Field of view. The DWARF II shows 3.19° × 1.79° against 2.55° × 1.44°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Vespera II needs a mosaic or a tight crop.

Detail. The Vespera II samples at 2.39″ per pixel against 2.99″, so it pulls finer structure from small targets: planetary nebulae, globular cores, galaxy arms.

Subs and dark skies. The Vespera II goes up to 30 s subs in Expert Mode, the DWARF II tops out at 15 s. That matters little from a city, where skyglow sets the floor, and a lot from a dark site, where read noise does.

Filters. Neither has a built-in dual-band filter, so emission nebulae from a lit sky are slow going on both.

Specifications side by side

SpecDWARF IIVespera II
Aperture24 mm50 mm
Focal length100 mm (f/4.2)250 mm (f/5.0)
SensorSony IMX415, 8.3 MPSony IMX585, 8.3 MP
Pixel size1.45 µm2.9 µm
Pixel scale2.99″/px2.39″/px
Field of view3.19° × 1.79°2.55° × 1.44°
Sub exposures15 s10 s, 20 s, 30 s
Dual-band filterNoneClip-on option (Dual Band filter)
“No filter” positionAstroNo filter
Read noise used1.2 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.
TargetDWARF IIVespera IIFaster
Andromeda GalaxyGalaxy4 h 59 min1,198 subs1 h 27 min525 subsVespera II 3×
Orion NebulaEmission nebula57 min228 subs17 min103 subsVespera II 3×
North America NebulaEmission nebula7 h 45 min1,860 subs2 h 15 min813 subsVespera II 3×
Pinwheel GalaxyGalaxy16 h3,817 subs4 h 37 min1,661 subsVespera II 3×
Ring NebulaPlanetary nebula25 min101 subs8 min47 subsVespera II 3×
Western Veil NebulaSupernova remnant8 h 29 min2,035 subs2 h 28 min889 subsVespera II 3×
Hercules ClusterGlobular cluster24 min97 subs7 min44 subsVespera II 3×
PleiadesReflection nebula9 h 16 min2,225 subs2 h 42 min971 subsVespera II 3×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
TargetDWARF IIVespera IIFaster
Andromeda GalaxyGalaxy2 h 31 min603 subs34 min204 subsVespera II 4×
Orion NebulaEmission nebula31 min126 subs8 min47 subsVespera II 4×
North America NebulaEmission nebula3 h 50 min922 subs51 min306 subsVespera II 5×
Pinwheel GalaxyGalaxy7 h 44 min1,856 subs1 h 40 min602 subsVespera II 5×
Ring NebulaPlanetary nebula16 min64 subs5 min30 subsVespera II 3×
Western Veil NebulaSupernova remnant4 h 11 min1,006 subs55 min333 subsVespera II 5×
Hercules ClusterGlobular cluster14 min57 subs5 min30 subsVespera II 2.8×
PleiadesReflection nebula4 h 34 min1,097 subs1 h362 subsVespera II 5×

Try the DWARF II in the calculator Try the Vespera II

About the DwarfLab DWARF II

The original pocket scope. 24 mm aperture and tiny 1.45 µm pixels mean it is slow per pixel, so bin or downsample and be patient.

Where to buy the DWARF IIAmazon UKAmazon USAffiliate links: As an Amazon Associate I earn from qualifying purchases, at no cost to you.

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.

Where to buy the Vespera IIVaonis store DirectAmazon UKAmazon 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

DWARF II

Vespera II

All comparisons · Buying guide · DWARF II page · Vespera II page