How long to image the M22 with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 11 min (160 subs of 4 s) for a solid image of the M22. A quick look takes 3 min; a showpiece 43 min. Under a Bortle 3 rural sky the solid figure drops to 7 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it only just fits, at 94% of the short side.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 2 min24 subs | 6 min94 subs | 25 min375 subs |
| Bortle 2Typical dark site | 2 min24 subs | 6 min96 subs | 26 min383 subs |
| Bortle 3Rural | 2 min25 subs | 7 min100 subs | 27 min399 subs |
| Bortle 4Rural / suburban transition | 2 min28 subs | 7 min109 subs | 29 min436 subs |
| Bortle 5Suburban | 2 min31 subs | 8 min124 subs | 33 min495 subs |
| Bortle 6Bright suburban | 3 min40 subs | 11 min160 subs | 43 min640 subs |
| Bortle 7Suburban / urban transition | 4 min58 subs | 15 min229 subs | 1 h 01 min916 subs |
| Bortle 8City | 6 min85 subs | 22 min337 subs | 1 h 30 min1,345 subs |
| Bortle 9Inner city | 9 min142 subs | 38 min566 subs | 2 h 31 min2,261 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 14 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.
- 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 M22 is 32′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it only just fits, at 94% of the short side. Centre it carefully: there is no room to crop back afterwards.
About the M22
One of the brightest globulars in the sky, outshining M13, but low from northern Europe. Superb from the south.
NGC 6656 · Globular cluster in Sagittarius · magnitude 5.1 · 32′ · best in Jun, Jul, Aug. 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 M22 from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M22 with the ZWO Seestar S50: 12 min from Bortle 6
- M22 with the ZWO Seestar S50 Pro: 13 min from Bortle 6
- M22 with the ZWO Seestar S30: 13 min from Bortle 6
- M22 with the ZWO Seestar S30 Pro: 14 min from Bortle 6
- M22 with the DwarfLab DWARF 3: 18 min from Bortle 6
- M22 with the DwarfLab DWARF mini: 12 min from Bortle 6
- M22 with the DwarfLab Draco: 15 min from Bortle 6
- M22 with the DwarfLab DWARF II: 41 min from Bortle 6
- M22 with the Vaonis Vespera II: 12 min from Bortle 6
- M22 with the Vaonis Vespera Pro: 27 min from Bortle 6
- M22 with the Vaonis Vespera 3: 12 min from Bortle 6
- M22 with the Vaonis Vespera Pro 2: 26 min from Bortle 6
- M22 with the Unistellar Odyssey: 48 min from Bortle 6
- M22 with the Celestron Origin: 5 min from Bortle 6
- M22 with the Celestron Origin Mark II: 5 min from Bortle 6