How long to image the M5 with the Unistellar eQuinox 2

From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 9 min (132 subs of 4 s) for a solid image of the M5. A quick look takes 2 min; a showpiece 35 min. Under a Bortle 3 rural sky the solid figure drops to 6 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 67% of the frame’s short side.

M5 with the Unistellar eQuinox 2: 4 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site1 min20 subs5 min78 subs21 min312 subs
Bortle 2Typical dark site1 min20 subs5 min80 subs21 min318 subs
Bortle 3Rural1 min21 subs6 min83 subs22 min331 subs
Bortle 4Rural / suburban transition2 min23 subs6 min91 subs24 min361 subs
Bortle 5Suburban2 min26 subs7 min102 subs27 min408 subs
Bortle 6Bright suburban2 min33 subs9 min132 subs35 min525 subs
Bortle 7Suburban / urban transition3 min47 subs12 min187 subs50 min748 subs
Bortle 8City5 min69 subs18 min274 subs1 h 13 min1,094 subs
Bortle 9Inner city8 min115 subs31 min458 subs2 h 02 min1,831 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 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.)

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How it frames

The M5 is 23′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 67% of the frame’s short side.

About the M5

A bright, slightly elliptical globular in Serpens that rivals M13 and resolves into stars quickly.

NGC 5904 · Globular cluster in Serpens · magnitude 5.7 · 23′ · best in Apr, May, Jun. 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 M5 with your eQuinox 2? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M5 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 M5 · All targets for the eQuinox 2