How long to image the M3 with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 37 min (560 subs of 4 s) for a solid image of the M3. A quick look takes 9 min; a showpiece 2 h 29 min. Under a Bortle 3 rural sky the solid figure drops to 26 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.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 6 min95 subs | 25 min377 subs | 1 h 40 min1,506 subs |
| Bortle 2Typical dark site | 6 min96 subs | 25 min383 subs | 1 h 42 min1,529 subs |
| Bortle 3Rural | 7 min99 subs | 26 min393 subs | 1 h 45 min1,571 subs |
| Bortle 4Rural / suburban transition | 7 min105 subs | 28 min419 subs | 1 h 52 min1,674 subs |
| Bortle 5Suburban | 8 min115 subs | 31 min460 subs | 2 h 02 min1,838 subs |
| Bortle 6Bright suburban | 9 min140 subs | 37 min560 subs | 2 h 29 min2,238 subs |
| Bortle 7Suburban / urban transition | 13 min188 subs | 50 min751 subs | 3 h 20 min3,002 subs |
| Bortle 8City | 17 min262 subs | 1 h 10 min1,047 subs | 4 h 39 min4,188 subs |
| Bortle 9Inner city | 28 min420 subs | 1 h 52 min1,679 subs | 7 h 28 min6,716 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 48 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 M3 is 18′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ 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 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 M3 from a Odyssey? 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 eQuinox 2: 8 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