How long to image the Owl Nebula with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 3 h 36 min (3,243 subs of 4 s) for a solid image of the Owl Nebula. A quick look takes 54 min; a showpiece 14 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 28 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 10% 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 | 35 min530 subs | 2 h 21 min2,119 subs | 9 h 25 min8,475 subs |
| Bortle 2Typical dark site | 36 min539 subs | 2 h 24 min2,154 subs | 9 h 34 min8,613 subs |
| Bortle 3Rural | 37 min555 subs | 2 h 28 min2,219 subs | 9 h 52 min8,875 subs |
| Bortle 4Rural / suburban transition | 40 min595 subs | 2 h 38 min2,377 subs | 11 h9,508 subs |
| Bortle 5Suburban | 44 min657 subs | 2 h 55 min2,628 subs | 12 h10,511 subs |
| Bortle 6Bright suburban | 54 min811 subs | 3 h 36 min3,243 subs | 14 h12,972 subs |
| Bortle 7Suburban / urban transition | 1 h 14 min1,104 subs | 4 h 54 min4,416 subs | 20 h17,662 subs |
| Bortle 8City | 1 h 44 min1,559 subs | 6 h 56 min6,236 subs | 28 h24,944 subs |
| Bortle 9Inner city | 2 h 49 min2,530 subs | 11 h10,119 subs | 45 h40,474 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 4 h 41 min of run time. The Odyssey’s battery is rated at about 5 h, which is cutting it fine; take a power bank. (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 Owl Nebula is 3.4′ × 3.3′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it fills 10% of the frame’s short side.
Filters
The Owl Nebula is an emission target, where a dual-band filter would normally cut the time several-fold from a lit sky, but the Odyssey has no dual-band option: No filter option; Unistellar says third-party filters cannot be fitted to the Odyssey. The figures above are for the No filter position, and a darker sky is the lever that remains.
About the Owl Nebula
A round planetary with two dark eyes. Large for its class and low in surface brightness; dual-band helps a lot.
M97, NGC 3587 · Planetary nebula in Ursa Major · magnitude 9.9 · 3.4′ × 3.3′ · best in Feb, Mar, Apr. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Planetary nebulae are small but intensely bright per pixel in OIII and H-alpha, so they respond very well to a dual-band filter and do not need much time for the main shell. The faint outer halos most of them have are a different proposition and need hours. Keep subs short if the central region saturates.
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 Owl Nebula from a Odyssey? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Owl Nebula with the ZWO Seestar S50: 38 min from Bortle 6
- Owl Nebula with the ZWO Seestar S50 Pro: 42 min from Bortle 6
- Owl Nebula with the ZWO Seestar S30: 43 min from Bortle 6
- Owl Nebula with the ZWO Seestar S30 Pro: 45 min from Bortle 6
- Owl Nebula with the DwarfLab DWARF 3: 49 min from Bortle 6
- Owl Nebula with the DwarfLab DWARF mini: 37 min from Bortle 6
- Owl Nebula with the DwarfLab Draco: 30 min from Bortle 6
- Owl Nebula with the DwarfLab DWARF II: 3 h from Bortle 6
- Owl Nebula with the Vaonis Vespera II: 54 min from Bortle 6
- Owl Nebula with the Vaonis Vespera Pro: 1 h 59 min from Bortle 6
- Owl Nebula with the Vaonis Vespera 3: 51 min from Bortle 6
- Owl Nebula with the Vaonis Vespera Pro 2: 1 h 54 min from Bortle 6
- Owl Nebula with the Unistellar eQuinox 2: 47 min from Bortle 6
- Owl Nebula with the Celestron Origin: 14 min from Bortle 6
- Owl Nebula with the Celestron Origin Mark II: 20 min from Bortle 6
All telescopes for the Owl Nebula · All targets for the Odyssey