How long to image the Hercules Cluster with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 28 min (419 subs of 4 s) for a solid image of the Hercules Cluster. A quick look takes 7 min; a showpiece 1 h 51 min. Under a Bortle 3 rural sky the solid figure drops to 20 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 59% 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 | 5 min72 subs | 19 min285 subs | 1 h 16 min1,139 subs |
| Bortle 2Typical dark site | 5 min73 subs | 19 min289 subs | 1 h 17 min1,155 subs |
| Bortle 3Rural | 5 min75 subs | 20 min297 subs | 1 h 19 min1,186 subs |
| Bortle 4Rural / suburban transition | 5 min79 subs | 21 min316 subs | 1 h 24 min1,261 subs |
| Bortle 5Suburban | 6 min87 subs | 23 min346 subs | 1 h 32 min1,381 subs |
| Bortle 6Bright suburban | 7 min105 subs | 28 min419 subs | 1 h 51 min1,673 subs |
| Bortle 7Suburban / urban transition | 9 min140 subs | 37 min558 subs | 2 h 29 min2,230 subs |
| Bortle 8City | 13 min194 subs | 52 min774 subs | 3 h 26 min3,095 subs |
| Bortle 9Inner city | 21 min309 subs | 1 h 22 min1,235 subs | 5 h 29 min4,939 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 36 min of run time. The Odyssey’s battery (rated about 5 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 power bank 20000mAh 5V 2.4AUnistellar says plain 5 V 2.4 A and warns against fast or adaptive chargers.
- 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 Odyssey →
How it frames
The Hercules Cluster is 20′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it fills 59% of the frame’s short side.
About the Hercules Cluster
The great northern globular, a few hundred thousand stars in a ball a third the Moon's width. Quick and always satisfying.
M13, NGC 6205 · Globular cluster in Hercules · magnitude 5.8 · 20′ · best in May, Jun, Jul. 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 Odyssey
Unistellar’s compact 85 mm with autofocus and tiny pixels. Sharp, but the fine sampling costs time on faint extended targets. The Odyssey Pro is the same telescope with an eyepiece added, so these figures apply to both.
Fixed 4 s subs in Enhanced Vision; they cannot be changed. No filter option; Unistellar says third-party filters cannot be fitted to the Odyssey.
The Odyssey 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 Hercules Cluster from a Odyssey? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Hercules Cluster with the ZWO Seestar S50: 7 min from Bortle 6
- Hercules Cluster with the ZWO Seestar S50 Pro: 8 min from Bortle 6
- Hercules Cluster with the ZWO Seestar S30: 8 min from Bortle 6
- Hercules Cluster with the ZWO Seestar S30 Pro: 8 min from Bortle 6
- Hercules Cluster with the DwarfLab DWARF 3: 11 min from Bortle 6
- Hercules Cluster with the DwarfLab DWARF mini: 8 min from Bortle 6
- Hercules Cluster with the DwarfLab Draco: 15 min from Bortle 6
- Hercules Cluster with the DwarfLab DWARF II: 24 min from Bortle 6
- Hercules Cluster with the Vaonis Vespera II: 7 min from Bortle 6
- Hercules Cluster with the Vaonis Vespera Pro: 16 min from Bortle 6
- Hercules Cluster with the Vaonis Vespera 3: 7 min from Bortle 6
- Hercules Cluster with the Vaonis Vespera Pro 2: 15 min from Bortle 6
- Hercules Cluster with the Unistellar eQuinox 2: 6 min from Bortle 6
- Hercules Cluster with the Celestron Origin: 5 min from Bortle 6
- Hercules Cluster with the Celestron Origin Mark II: 5 min from Bortle 6
All telescopes for the Hercules Cluster · All targets for the Odyssey