How Many Subs

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

DwarfLab DWARF II against Unistellar Odyssey, 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 DWARF II 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 DWARF II is 1.6× faster.

Field of view. The DWARF II shows 3.19° × 1.79° against 0.75° × 0.56°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the Odyssey needs a mosaic or a tight crop.

Detail. The Odyssey samples at 0.93″ per pixel against 2.99″, so it pulls finer structure from small targets: planetary nebulae, globular cores, galaxy arms.

Subs and dark skies. The DWARF II goes up to 15 s subs, the Odyssey tops out at 4 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 IIOdyssey
Aperture24 mm85 mm
Focal length100 mm (f/4.2)320 mm (f/3.8)
SensorSony IMX415, 8.3 MPIMX415-class, 1.45 µm (Unistellar does not name it), 6.2 MP
Pixel size1.45 µm1.45 µm
Pixel scale2.99″/px0.93″/px
Field of view3.19° × 1.79°0.75° × 0.56°
Sub exposures15 s4 s
Dual-band filterNoneNone
“No filter” positionAstroNo filter
Read noise used1.2 e⁻1.2 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 IIOdysseyFaster
Andromeda GalaxyGalaxy4 h 59 min1,198 subs6 h 07 min5,505 subsDWARF II 1.2×
Orion NebulaEmission nebula57 min228 subs1 h 08 min1,016 subsDWARF II 1.2×
North America NebulaEmission nebula7 h 45 min1,860 subs9 h 33 min8,594 subsDWARF II 1.2×
Pinwheel GalaxyGalaxy16 h3,817 subs20 h17,741 subsDWARF II 1.2×
Ring NebulaPlanetary nebula25 min101 subs28 min422 subsDWARF II 1.1×
Western Veil NebulaSupernova remnant8 h 29 min2,035 subs10 h9,406 subsDWARF II 1.2×
Hercules ClusterGlobular cluster24 min97 subs28 min419 subsDWARF II 1.2×
PleiadesReflection nebula9 h 16 min2,225 subs11 h10,297 subsDWARF II 1.2×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
TargetDWARF IIOdysseyFaster
Andromeda GalaxyGalaxy2 h 31 min603 subs4 h 05 min3,683 subsDWARF II 1.6×
Orion NebulaEmission nebula31 min126 subs47 min701 subsDWARF II 1.5×
North America NebulaEmission nebula3 h 50 min922 subs6 h 21 min5,721 subsDWARF II 1.7×
Pinwheel GalaxyGalaxy7 h 44 min1,856 subs13 h11,739 subsDWARF II 1.7×
Ring NebulaPlanetary nebula16 min64 subs21 min309 subsDWARF II 1.3×
Western Veil NebulaSupernova remnant4 h 11 min1,006 subs6 h 57 min6,257 subsDWARF II 1.7×
Hercules ClusterGlobular cluster14 min57 subs20 min297 subsDWARF II 1.4×
PleiadesReflection nebula4 h 34 min1,097 subs7 h 36 min6,843 subsDWARF II 1.7×

Try the DWARF II in the calculator Try the Odyssey

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 Unistellar Odyssey

Unistellar’s compact 85 mm with autofocus and tiny pixels. Sharp, but the fine sampling costs time on faint extended targets. The Odyssey Pro is the same telescope with an eyepiece added, so these figures apply to both.

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

Other comparisons

DWARF II

Odyssey

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