How Many Subs

DWARF 3 vs DWARF II: which is faster for deep-sky imaging?

DwarfLab DWARF 3 against DwarfLab DWARF 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 DWARF 3 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 DWARF 3 is 3× faster.

Field of view. The DWARF II shows 3.19° × 1.79° against 2.93° × 1.65°, so big targets such as the Andromeda Galaxy, the North America Nebula and the Pleiades fit with room to spare where the DWARF 3 needs a mosaic or a tight crop.

Detail. Pixel scales are within 10% of each other, so neither has a real detail advantage.

Subs and dark skies. The DWARF 3 goes up to 60 s subs in EQ 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. The DWARF 3 has a dual-band filter built in; the DWARF II does not, which costs it heavily on emission nebulae from any suburban sky.

Specifications side by side

SpecDWARF 3DWARF II
Aperture35 mm24 mm
Focal length150 mm (f/4.3)100 mm (f/4.2)
SensorSony IMX678, 8.3 MPSony IMX415, 8.3 MP
Pixel size2 µm1.45 µm
Pixel scale2.75″/px2.99″/px
Field of view2.93° × 1.65°3.19° × 1.79°
Sub exposures15 s, 30 s, 60 s15 s
Dual-band filterBuilt in (Dual-band)None
“No filter” positionAstroAstro
Read noise used0.6 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 3DWARF IIFaster
Andromeda GalaxyGalaxy2 h 07 min509 subs4 h 59 min1,198 subsDWARF 3 2.4×
Orion NebulaEmission nebula16 min66 subs57 min228 subsDWARF 3 3×
North America NebulaEmission nebula1 h 46 min424 subs7 h 45 min1,860 subsDWARF 3 4×
Pinwheel GalaxyGalaxy6 h 41 min1,604 subs16 h3,817 subsDWARF 3 2.4×
Ring NebulaPlanetary nebula10 min39 subs25 min101 subsDWARF 3 2.6×
Western Veil NebulaSupernova remnant1 h 55 min460 subs8 h 29 min2,035 subsDWARF 3 4×
Hercules ClusterGlobular cluster11 min44 subs24 min97 subsDWARF 3 2.2×
PleiadesReflection nebula3 h 55 min939 subs9 h 16 min2,225 subsDWARF 3 2.4×

Rural sky (Bortle 3)

Total integration for a solid image from a Bortle 3 sky, default subs, recommended filter for each scope.
TargetDWARF 3DWARF IIFaster
Andromeda GalaxyGalaxy44 min178 subs2 h 31 min603 subsDWARF 3 3×
Orion NebulaEmission nebula12 min48 subs31 min126 subsDWARF 3 2.6×
North America NebulaEmission nebula1 h 06 min264 subs3 h 50 min922 subsDWARF 3 3×
Pinwheel GalaxyGalaxy2 h 08 min514 subs7 h 44 min1,856 subsDWARF 3 4×
Ring NebulaPlanetary nebula8 min33 subs16 min64 subsDWARF 3 2.0×
Western Veil NebulaSupernova remnant1 h 11 min285 subs4 h 11 min1,006 subsDWARF 3 4×
Hercules ClusterGlobular cluster8 min30 subs14 min57 subsDWARF 3 1.9×
PleiadesReflection nebula1 h 18 min312 subs4 h 34 min1,097 subsDWARF 3 4×

Try the DWARF 3 in the calculator Try the DWARF II

About the DwarfLab DWARF 3

Small pixels on a 35 mm f/4.3 lens give a sharper image than its aperture suggests, and EQ mode with 60 s subs makes it the read-noise winner in dark skies.

Where to buy the DWARF 3DwarfLab store UKDwarfLab store USAmazon UKAmazon USThe DwarfLab 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 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.

Other comparisons

DWARF 3

DWARF II

All comparisons · Buying guide · DWARF 3 page · DWARF II page