How long to image the Lagoon Nebula with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 25 min (376 subs of 4 s) for a solid image of the Lagoon Nebula. A quick look takes 6 min; a showpiece 1 h 40 min. Under a Bortle 3 rural sky the solid figure drops to 15 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it is 2.6× wider than the frame.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 4 min53 subs | 14 min211 subs | 56 min842 subs |
| Bortle 2Typical dark site | 4 min54 subs | 14 min216 subs | 57 min862 subs |
| Bortle 3Rural | 4 min57 subs | 15 min226 subs | 1 h901 subs |
| Bortle 4Rural / suburban transition | 4 min63 subs | 17 min249 subs | 1 h 06 min994 subs |
| Bortle 5Suburban | 5 min72 subs | 19 min286 subs | 1 h 16 min1,141 subs |
| Bortle 6Bright suburban | 6 min94 subs | 25 min376 subs | 1 h 40 min1,502 subs |
| Bortle 7Suburban / urban transition | 9 min137 subs | 37 min548 subs | 2 h 26 min2,191 subs |
| Bortle 8City | 14 min204 subs | 54 min816 subs | 3 h 37 min3,261 subs |
| Bortle 9Inner city | 23 min347 subs | 1 h 32 min1,386 subs | 6 h 09 min5,541 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 33 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 Lagoon Nebula is 90′ × 40′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it is 2.6× wider than the frame. A mosaic, or choosing the part you want and letting the rest go, is how it gets shot on this scope.
Filters
The Lagoon 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 Lagoon Nebula
The showpiece emission nebula of the summer Milky Way, bright enough to catch its core in minutes. Pair it with the Trifid in one wide frame.
M8, NGC 6523 · Emission nebula in Sagittarius · magnitude 6.0 · 90′ × 40′ · best in Jun, Jul, Aug. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Emission nebulae glow in a few narrow lines, mostly hydrogen-alpha (deep red) and doubly ionised oxygen (teal). A dual-band filter passes those lines and blocks most skyglow, which is why it cuts the time needed from a suburban sky so dramatically. Use it. From a genuinely dark site the gain is smaller because there is less skyglow to block, and read noise becomes the limit, which is where longer subs (EQ mode, or Expert Mode on a Vespera) earn their keep.
Stars lose colour through a dual-band filter; a short broadband stack blended in fixes that if you care.
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 Lagoon 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
- Lagoon Nebula with the ZWO Seestar S50: 20 min from Bortle 6
- Lagoon Nebula with the ZWO Seestar S50 Pro: 22 min from Bortle 6
- Lagoon Nebula with the ZWO Seestar S30: 22 min from Bortle 6
- Lagoon Nebula with the ZWO Seestar S30 Pro: 24 min from Bortle 6
- Lagoon Nebula with the DwarfLab DWARF 3: 25 min from Bortle 6
- Lagoon Nebula with the DwarfLab DWARF mini: 19 min from Bortle 6
- Lagoon Nebula with the DwarfLab Draco: 16 min from Bortle 6
- Lagoon Nebula with the DwarfLab DWARF II: 1 h 35 min from Bortle 6
- Lagoon Nebula with the Vaonis Vespera II: 28 min from Bortle 6
- Lagoon Nebula with the Vaonis Vespera Pro: 1 h 03 min from Bortle 6
- Lagoon Nebula with the Vaonis Vespera 3: 27 min from Bortle 6
- Lagoon Nebula with the Vaonis Vespera Pro 2: 1 h from Bortle 6
- Lagoon Nebula with the Unistellar Odyssey: 1 h 55 min from Bortle 6
- Lagoon Nebula with the Celestron Origin: 7 min from Bortle 6
- Lagoon Nebula with the Celestron Origin Mark II: 10 min from Bortle 6
All telescopes for the Lagoon Nebula · All targets for the eQuinox 2