How long to image the M10 with the DwarfLab DWARF mini

From a Bortle 6 suburban sky, the DwarfLab DWARF mini needs about 27 min (110 subs of 15 s) for a solid image of the M10. A quick look takes 7 min; a showpiece 1 h 49 min. Under a Bortle 3 rural sky the solid figure drops to 12 min. At Bortle 6 the limit is skyglow, so a darker site or a filter helps more than longer subs. In this scope's field it fills 28% of the frame’s short side.

M10 with the DwarfLab DWARF mini: 15 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site3 min11 subs10 min41 subs41 min163 subs
Bortle 2Typical dark site3 min11 subs11 min43 subs43 min172 subs
Bortle 3Rural3 min12 subs12 min47 subs47 min188 subs
Bortle 4Rural / suburban transition4 min15 subs14 min57 subs56 min226 subs
Bortle 5Suburban4 min18 subs18 min72 subs1 h 12 min287 subs
Bortle 6Bright suburban7 min28 subs27 min110 subs1 h 49 min437 subs
Bortle 7Suburban / urban transition11 min46 subs45 min181 subs3 h 01 min723 subs
Bortle 8City18 min73 subs1 h 13 min292 subs4 h 52 min1,167 subs
Bortle 9Inner city33 min133 subs2 h 12 min529 subs8 h 48 min2,114 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 36 min of run time. The DWARF mini’s battery (rated about 3 h 30 min) 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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Everything that fits the DWARF mini →

How it frames

The M10 is 20′ across. The DWARF mini frames 2.13° × 1.20° at 3.99″ per pixel, so it fills 28% of the frame’s short side.

Longer subs

Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 90 s is the ceiling. Time for a solid image by sub length:

Sub lengthBortle 3Bortle 5Bortle 7
15 s12 min47 subs18 min72 subs45 min181 subs
30 s15 min30 subs17 min34 subs44 min88 subs
60 s30 min30 subs30 min30 subs43 min44 subs
90 s45 min30 subs45 min30 subs45 min30 subs

Leave the dual-band filter out for the M10. It is a globular cluster, and it shines right across the spectrum. A dual-band filter keeps two emission lines and throws the rest away, so most of the light you came for is being stopped along with the sky. From a Bortle 6 sky it would be roughly 11 times slower.

About the M10

A bright globular in Ophiuchus, three degrees from its twin M12. Both fit a short session.

NGC 6254 · Globular cluster in Ophiuchus · magnitude 6.6 · 20′ · best in May, Jun, Jul. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Globular clusters are point sources packed tight, so they come quickly: the core resolves into stars within a handful of minutes on any smart scope. More time deepens the halo and pulls in the faint outer members. Use short subs so the core does not saturate into a white blob, and no filter.

About the DwarfLab DWARF mini

DwarfLab’s answer to the Seestar S30: same sensor and focal length, big pixels, dual-band filter built in, and 90 s subs in EQ mode. Sensitivity over megapixels.

Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 90 s is the ceiling. Built-in Astro (430 to 690 nm), dark-frame and dual-band Hα / OIII filters; no plain VIS filter on the tele camera.

Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 15 s and 90 s subs is small; from a rural site it can halve the total time, especially with a dual-band filter in place.

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 M10 with your DWARF mini? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M10 from a DWARF mini? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the M10 · All targets for the DWARF mini