How long to image the Owl Nebula with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 47 min (710 subs of 4 s) for a solid image of the Owl Nebula. A quick look takes 12 min; a showpiece 3 h 09 min. Under a Bortle 3 rural sky the solid figure drops to 29 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 | 7 min101 subs | 27 min401 subs | 1 h 47 min1,604 subs |
| Bortle 2Typical dark site | 7 min103 subs | 27 min411 subs | 1 h 49 min1,642 subs |
| Bortle 3Rural | 7 min108 subs | 29 min429 subs | 1 h 54 min1,714 subs |
| Bortle 4Rural / suburban transition | 8 min118 subs | 31 min472 subs | 2 h 06 min1,888 subs |
| Bortle 5Suburban | 9 min136 subs | 36 min541 subs | 2 h 24 min2,164 subs |
| Bortle 6Bright suburban | 12 min178 subs | 47 min710 subs | 3 h 09 min2,840 subs |
| Bortle 7Suburban / urban transition | 17 min259 subs | 1 h 09 min1,033 subs | 4 h 35 min4,129 subs |
| Bortle 8City | 26 min384 subs | 1 h 42 min1,533 subs | 6 h 49 min6,131 subs |
| Bortle 9Inner city | 43 min650 subs | 2 h 53 min2,600 subs | 12 h10,399 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 02 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 Owl Nebula is 3.4′ × 3.3′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ 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 eQuinox 2 has no dual-band option: 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 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 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 Owl Nebula from a eQuinox 2? 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 Odyssey: 3 h 36 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 eQuinox 2