How long to image the M3 with the Unistellar eQuinox 2

From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 8 min (125 subs of 4 s) for a solid image of the M3. A quick look takes 2 min; a showpiece 33 min. Under a Bortle 3 rural sky the solid figure drops to 5 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 53% of the frame’s short side.

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.)

• USB-C power bank 20000mAh 5V 2AUnistellar asks for a 5 V 2 A output; PD is not needed.
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• red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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Everything that fits the eQuinox 2 →

How it frames

The M3 is 18′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 53% of the frame’s short side.

About the M3

One of the finest northern globulars, half a million stars in a tight ball. A spring showpiece that needs little time.

NGC 5272 · Globular cluster in Canes Venatici · magnitude 6.2 · 18′ · best in Mar, Apr, May. 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.

Have an image of the M3 from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

• M3 with the ZWO Seestar S50: 10 min from Bortle 6
• M3 with the ZWO Seestar S50 Pro: 11 min from Bortle 6
• M3 with the ZWO Seestar S30: 10 min from Bortle 6
• M3 with the ZWO Seestar S30 Pro: 11 min from Bortle 6
• M3 with the DwarfLab DWARF 3: 14 min from Bortle 6
• M3 with the DwarfLab DWARF mini: 10 min from Bortle 6
• M3 with the DwarfLab Draco: 15 min from Bortle 6
• M3 with the DwarfLab DWARF II: 32 min from Bortle 6
• M3 with the Vaonis Vespera II: 10 min from Bortle 6
• M3 with the Vaonis Vespera Pro: 21 min from Bortle 6
• M3 with the Vaonis Vespera 3: 9 min from Bortle 6
• M3 with the Vaonis Vespera Pro 2: 20 min from Bortle 6
• M3 with the Unistellar Odyssey: 37 min from Bortle 6
• M3 with the Celestron Origin: 5 min from Bortle 6
• M3 with the Celestron Origin Mark II: 5 min from Bortle 6

All telescopes for the M3 · All targets for the eQuinox 2