How long to image the Trifid Nebula with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 1 h (907 subs of 4 s) for a solid image of the Trifid Nebula. A quick look takes 15 min; a showpiece 4 h 02 min. Under a Bortle 3 rural sky the solid figure drops to 35 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 82% 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 | 8 min123 subs | 33 min492 subs | 2 h 11 min1,967 subs |
| Bortle 2Typical dark site | 8 min127 subs | 34 min505 subs | 2 h 15 min2,018 subs |
| Bortle 3Rural | 9 min133 subs | 35 min529 subs | 2 h 21 min2,114 subs |
| Bortle 4Rural / suburban transition | 10 min147 subs | 39 min587 subs | 2 h 36 min2,348 subs |
| Bortle 5Suburban | 11 min170 subs | 45 min680 subs | 3 h 01 min2,718 subs |
| Bortle 6Bright suburban | 15 min227 subs | 1 h907 subs | 4 h 02 min3,626 subs |
| Bortle 7Suburban / urban transition | 22 min335 subs | 1 h 29 min1,339 subs | 5 h 57 min5,356 subs |
| Bortle 8City | 34 min503 subs | 2 h 14 min2,011 subs | 8 h 56 min8,042 subs |
| Bortle 9Inner city | 57 min861 subs | 3 h 50 min3,443 subs | 15 h13,771 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 19 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 Trifid Nebula is 28′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 82% of the frame’s short side.
Filters
The Trifid 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 Trifid Nebula
Red emission, blue reflection and dark lanes in one object. Shoot it without a filter to keep the blue, or dual-band for the red.
M20, NGC 6514 · Emission nebula in Sagittarius · magnitude 6.3 · 28′ · 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 Trifid 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
- Trifid Nebula with the ZWO Seestar S50: 44 min from Bortle 6
- Trifid Nebula with the ZWO Seestar S50 Pro: 49 min from Bortle 6
- Trifid Nebula with the ZWO Seestar S30: 51 min from Bortle 6
- Trifid Nebula with the ZWO Seestar S30 Pro: 53 min from Bortle 6
- Trifid Nebula with the DwarfLab DWARF 3: 55 min from Bortle 6
- Trifid Nebula with the DwarfLab DWARF mini: 43 min from Bortle 6
- Trifid Nebula with the DwarfLab Draco: 35 min from Bortle 6
- Trifid Nebula with the DwarfLab DWARF II: 3 h 48 min from Bortle 6
- Trifid Nebula with the Vaonis Vespera II: 1 h 07 min from Bortle 6
- Trifid Nebula with the Vaonis Vespera Pro: 2 h 30 min from Bortle 6
- Trifid Nebula with the Vaonis Vespera 3: 1 h 04 min from Bortle 6
- Trifid Nebula with the Vaonis Vespera Pro 2: 2 h 23 min from Bortle 6
- Trifid Nebula with the Unistellar Odyssey: 4 h 39 min from Bortle 6
- Trifid Nebula with the Celestron Origin: 18 min from Bortle 6
- Trifid Nebula with the Celestron Origin Mark II: 24 min from Bortle 6
All telescopes for the Trifid Nebula · All targets for the eQuinox 2