How long to image the M78 with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 4 h 16 min (3,847 subs of 4 s) for a solid image of the M78. A quick look takes 1 h 04 min; a showpiece 17 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 54 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 24% 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 | 42 min623 subs | 2 h 46 min2,492 subs | 11 h9,968 subs |
| Bortle 2Typical dark site | 42 min634 subs | 2 h 49 min2,534 subs | 11 h10,135 subs |
| Bortle 3Rural | 44 min654 subs | 2 h 54 min2,613 subs | 12 h10,449 subs |
| Bortle 4Rural / suburban transition | 47 min701 subs | 3 h 07 min2,803 subs | 12 h11,212 subs |
| Bortle 5Suburban | 52 min777 subs | 3 h 27 min3,105 subs | 14 h12,420 subs |
| Bortle 6Bright suburban | 1 h 04 min962 subs | 4 h 16 min3,847 subs | 17 h15,385 subs |
| Bortle 7Suburban / urban transition | 1 h 28 min1,315 subs | 5 h 51 min5,259 subs | 23 h21,034 subs |
| Bortle 8City | 2 h 04 min1,863 subs | 8 h 17 min7,452 subs | 33 h29,805 subs |
| Bortle 9Inner city | 3 h 22 min3,032 subs | 13 h12,128 subs | 54 h48,512 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 5 h 33 min of run time. The Odyssey’s battery is rated at about 5 h, less near freezing, so the session needs an external power bank. (Bortle 6, solid image; we allow 30% over the integration time, and 30% off the battery for a December night.)
- 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.
- hand warmers long lastingAir-activated packs give hours of heat for the person; winter nights are long and you spend most of them standing still.
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Everything that fits the Odyssey →
How it frames
The M78 is 8′ × 6′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it fills 24% of the frame’s short side.
About the M78
The brightest reflection nebula in the sky, blue dust lit by young stars in Orion's belt. No filter; it is starlight.
NGC 2068 · Reflection nebula in Orion · magnitude 8.3 · 8′ × 6′ · best in Nov, Dec, Jan. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Reflection nebulae are starlight scattered by dust, so they are broadband and blue. A dual-band filter removes almost all of it; do not use one. These are among the faintest structures a smart scope can attempt and the figures run long. A dark sky matters more here than for any other type, and the Moon must be down.
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 M78 from a Odyssey? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M78 with the ZWO Seestar S50: 1 h 03 min from Bortle 6
- M78 with the ZWO Seestar S50 Pro: 1 h 09 min from Bortle 6
- M78 with the ZWO Seestar S30: 1 h 06 min from Bortle 6
- M78 with the ZWO Seestar S30 Pro: 1 h 13 min from Bortle 6
- M78 with the DwarfLab DWARF 3: 1 h 31 min from Bortle 6
- M78 with the DwarfLab DWARF mini: 1 h 02 min from Bortle 6
- M78 with the DwarfLab Draco: 52 min from Bortle 6
- M78 with the DwarfLab DWARF II: 3 h 32 min from Bortle 6
- M78 with the Vaonis Vespera II: 1 h 03 min from Bortle 6
- M78 with the Vaonis Vespera Pro: 2 h 20 min from Bortle 6
- M78 with the Vaonis Vespera 3: 1 h from Bortle 6
- M78 with the Vaonis Vespera Pro 2: 2 h 13 min from Bortle 6
- M78 with the Unistellar eQuinox 2: 56 min from Bortle 6
- M78 with the Celestron Origin: 17 min from Bortle 6
- M78 with the Celestron Origin Mark II: 23 min from Bortle 6