How long to image the NGC 663 with the DwarfLab DWARF II

From a Bortle 6 suburban sky, the DwarfLab DWARF II needs about 8 min (33 subs of 15 s) for a solid image of the NGC 663. A quick look takes 3 min; a showpiece 33 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 15% of the frame’s short side.

NGC 663 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 subs23 min90 subs
Bortle 2Typical dark site3 min10 subs8 min30 subs23 min90 subs
Bortle 3Rural3 min10 subs8 min30 subs23 min90 subs
Bortle 4Rural / suburban transition3 min10 subs8 min30 subs23 min94 subs
Bortle 5Suburban3 min10 subs8 min30 subs26 min105 subs
Bortle 6Bright suburban3 min10 subs8 min33 subs33 min132 subs
Bortle 7Suburban / urban transition3 min12 subs11 min46 subs46 min184 subs
Bortle 8City4 min17 subs16 min66 subs1 h 06 min264 subs
Bortle 9Inner city7 min28 subs27 min109 subs1 h 49 min435 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 11 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.)

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How it frames

The NGC 663 is 16′ across. The DWARF II frames 3.19° × 1.79° at 2.99″ per pixel, so it fills 15% of the frame’s short side.

About the NGC 663

A rich open cluster in Cassiopeia among several others. Good practice for short-sub star colour.

Caldwell 10 · Open cluster in Cassiopeia · magnitude 7.1 · 16′ · best in Sep, Oct, Nov. 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 663 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 663 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 663 · All targets for the DWARF II