How long to image the M54 with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 25 min (378 subs of 4 s) for a solid image of the M54. A quick look takes 6 min; a showpiece 1 h 41 min. Under a Bortle 3 rural sky the solid figure drops to 15 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 35% of the frame’s short side.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 4 min54 subs | 14 min214 subs | 57 min855 subs |
| Bortle 2Typical dark site | 4 min55 subs | 15 min219 subs | 58 min875 subs |
| Bortle 3Rural | 4 min58 subs | 15 min229 subs | 1 h 01 min913 subs |
| Bortle 4Rural / suburban transition | 4 min63 subs | 17 min252 subs | 1 h 07 min1,005 subs |
| Bortle 5Suburban | 5 min72 subs | 19 min288 subs | 1 h 17 min1,151 subs |
| Bortle 6Bright suburban | 6 min95 subs | 25 min378 subs | 1 h 41 min1,509 subs |
| Bortle 7Suburban / urban transition | 9 min138 subs | 37 min549 subs | 2 h 26 min2,193 subs |
| Bortle 8City | 14 min204 subs | 54 min814 subs | 3 h 37 min3,253 subs |
| Bortle 9Inner city | 23 min345 subs | 1 h 32 min1,379 subs | 6 h 08 min5,515 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 33 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 M54 is 12′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 35% of the frame’s short side.
About the M54
A globular that actually belongs to the Sagittarius Dwarf galaxy being eaten by the Milky Way. Low from the north.
NGC 6715 · Globular cluster in Sagittarius · magnitude 7.6 · 12′ · 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 M54 from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M54 with the ZWO Seestar S50: 28 min from Bortle 6
- M54 with the ZWO Seestar S50 Pro: 31 min from Bortle 6
- M54 with the ZWO Seestar S30: 30 min from Bortle 6
- M54 with the ZWO Seestar S30 Pro: 33 min from Bortle 6
- M54 with the DwarfLab DWARF 3: 42 min from Bortle 6
- M54 with the DwarfLab DWARF mini: 28 min from Bortle 6
- M54 with the DwarfLab Draco: 23 min from Bortle 6
- M54 with the DwarfLab DWARF II: 1 h 36 min from Bortle 6
- M54 with the Vaonis Vespera II: 28 min from Bortle 6
- M54 with the Vaonis Vespera Pro: 1 h 03 min from Bortle 6
- M54 with the Vaonis Vespera 3: 27 min from Bortle 6
- M54 with the Vaonis Vespera Pro 2: 1 h 01 min from Bortle 6
- M54 with the Unistellar Odyssey: 1 h 55 min from Bortle 6
- M54 with the Celestron Origin: 8 min from Bortle 6
- M54 with the Celestron Origin Mark II: 10 min from Bortle 6