How long to image the M79 with the Unistellar eQuinox 2

From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 14 min (206 subs of 4 s) for a solid image of the M79. A quick look takes 3 min; a showpiece 55 min. Under a Bortle 3 rural sky the solid figure drops to 9 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 26% of the frame’s short side.

M79 with the Unistellar eQuinox 2: 4 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site2 min31 subs8 min123 subs33 min489 subs
Bortle 2Typical dark site2 min32 subs8 min125 subs33 min500 subs
Bortle 3Rural2 min33 subs9 min130 subs35 min519 subs
Bortle 4Rural / suburban transition2 min36 subs9 min142 subs38 min566 subs
Bortle 5Suburban3 min40 subs11 min160 subs43 min640 subs
Bortle 6Bright suburban3 min52 subs14 min206 subs55 min822 subs
Bortle 7Suburban / urban transition5 min73 subs19 min292 subs1 h 18 min1,168 subs
Bortle 8City7 min107 subs28 min427 subs1 h 54 min1,706 subs
Bortle 9Inner city12 min179 subs48 min714 subs3 h 10 min2,853 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 18 min of run time. The eQuinox 2’s battery (rated about 11 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 M79 is 9′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 26% of the frame’s short side.

About the M79

A winter globular below Orion, unusual for the season. Low but compact.

NGC 1904 · Globular cluster in Lepus · magnitude 7.7 · 9′ · best in Nov, Dec, Jan. 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 Unistellar eQuinox 2

A 114 mm Newtonian with five times the light grasp of a 50 mm refractor. Fixed 4 s subs put it in read-noise territory under dark skies, but the aperture carries it. The published field is 45.6′ × 34.2′, a crop of the sensor.

Fixed 4 s subs in Enhanced Vision; they cannot be changed. No built-in filter. Unistellar sells only a solar filter and says a third-party filter is at your own risk and voids the warranty.

The eQuinox 2 uses fixed 4 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 M79 with your eQuinox 2? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M79 from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the M79 · All targets for the eQuinox 2