How long to image the NGC 1893 with the DwarfLab DWARF II

From a Bortle 6 suburban sky, the DwarfLab DWARF II needs about 11 min (45 subs of 15 s) for a solid image of the NGC 1893. A quick look takes 3 min; a showpiece 45 min. Under a Bortle 3 rural sky the solid figure drops to 8 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 10% of the frame’s short side.

NGC 1893 with the DwarfLab DWARF II: 15 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site3 min10 subs8 min30 subs28 min113 subs
Bortle 2Typical dark site3 min10 subs8 min30 subs29 min115 subs
Bortle 3Rural3 min10 subs8 min30 subs30 min119 subs
Bortle 4Rural / suburban transition3 min10 subs8 min32 subs32 min128 subs
Bortle 5Suburban3 min10 subs9 min36 subs36 min143 subs
Bortle 6Bright suburban3 min12 subs11 min45 subs45 min180 subs
Bortle 7Suburban / urban transition4 min16 subs16 min63 subs1 h 03 min251 subs
Bortle 8City6 min23 subs22 min90 subs1 h 30 min360 subs
Bortle 9Inner city9 min38 subs37 min149 subs2 h 28 min593 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 15 min of run time. The DWARF II’s battery (rated about 3 h) should cover it; a power bank still keeps the phone running the app alive. (Bortle 6, solid image; we allow 30% over the integration time, and 30% off the battery for a December night.)

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How it frames

The NGC 1893 is 11′ across. The DWARF II frames 3.19° × 1.79° at 2.99″ per pixel, so it fills 10% of the frame’s short side.

About the NGC 1893

The young cluster lighting the Tadpoles Nebula. Comes free in any IC 410 stack.

IC 410 cluster · Open cluster in Auriga · magnitude 7.5 · 11′ · best in Nov, Dec, Jan. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Open clusters are the easiest targets in the sky. The stars are bright, so the aim is colour and tight stars rather than depth: short subs, no filter, and stop before the bright members saturate. The nominal time here gets you clean star colour; more integration only adds background stars.

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.

15 s is the hard maximum in any mode; DwarfLab recommends EQ mode at 15 s. Two built-in filters, VIS and Astro (IR-pass); no dual-band. The optional UHC filter is no longer sold.

The DWARF II uses fixed 15 s subs, so the only levers you have are the sky you shoot from, the filter, and total time.

Stack across nights. Every smart scope app can continue a stack or you can combine the saved frames on a computer; the figures here are totals, not single-session limits.

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Imaged the NGC 1893 with your DWARF II? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the NGC 1893 from a DWARF II? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the NGC 1893 · All targets for the DWARF II