How long to image the M68 with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 28 min (420 subs of 4 s) for a solid image of the M68. A quick look takes 7 min; a showpiece 1 h 52 min. Under a Bortle 3 rural sky the solid figure drops to 17 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 32% 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 min60 subs | 16 min238 subs | 1 h 03 min949 subs |
| Bortle 2Typical dark site | 4 min61 subs | 16 min243 subs | 1 h 05 min972 subs |
| Bortle 3Rural | 4 min64 subs | 17 min254 subs | 1 h 08 min1,014 subs |
| Bortle 4Rural / suburban transition | 5 min70 subs | 19 min280 subs | 1 h 14 min1,117 subs |
| Bortle 5Suburban | 5 min80 subs | 21 min320 subs | 1 h 25 min1,279 subs |
| Bortle 6Bright suburban | 7 min105 subs | 28 min420 subs | 1 h 52 min1,679 subs |
| Bortle 7Suburban / urban transition | 10 min153 subs | 41 min610 subs | 2 h 43 min2,439 subs |
| Bortle 8City | 15 min227 subs | 1 h905 subs | 4 h 01 min3,620 subs |
| Bortle 9Inner city | 26 min384 subs | 1 h 42 min1,535 subs | 6 h 49 min6,138 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 36 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 M68 is 11′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 32% of the frame’s short side.
About the M68
A loose globular in Hydra, low from the UK but easy from lower latitudes.
NGC 4590 · Globular cluster in Hydra · magnitude 7.8 · 11′ · 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 M68 from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M68 with the ZWO Seestar S50: 32 min from Bortle 6
- M68 with the ZWO Seestar S50 Pro: 35 min from Bortle 6
- M68 with the ZWO Seestar S30: 33 min from Bortle 6
- M68 with the ZWO Seestar S30 Pro: 37 min from Bortle 6
- M68 with the DwarfLab DWARF 3: 46 min from Bortle 6
- M68 with the DwarfLab DWARF mini: 32 min from Bortle 6
- M68 with the DwarfLab Draco: 26 min from Bortle 6
- M68 with the DwarfLab DWARF II: 1 h 47 min from Bortle 6
- M68 with the Vaonis Vespera II: 32 min from Bortle 6
- M68 with the Vaonis Vespera Pro: 1 h 11 min from Bortle 6
- M68 with the Vaonis Vespera 3: 30 min from Bortle 6
- M68 with the Vaonis Vespera Pro 2: 1 h 07 min from Bortle 6
- M68 with the Unistellar Odyssey: 2 h 08 min from Bortle 6
- M68 with the Celestron Origin: 8 min from Bortle 6
- M68 with the Celestron Origin Mark II: 12 min from Bortle 6