How long to image the M61 with the Unistellar eQuinox 2
From a Bortle 6 suburban sky, the Unistellar eQuinox 2 needs about 2 h 50 min (2,547 subs of 4 s) for a solid image of the M61. A quick look takes 42 min; a showpiece 11 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 38 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 18% 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 | 23 min344 subs | 1 h 32 min1,373 subs | 6 h 06 min5,491 subs |
| Bortle 2Typical dark site | 23 min353 subs | 1 h 34 min1,409 subs | 6 h 16 min5,636 subs |
| Bortle 3Rural | 25 min370 subs | 1 h 38 min1,477 subs | 6 h 34 min5,908 subs |
| Bortle 4Rural / suburban transition | 27 min411 subs | 1 h 49 min1,643 subs | 7 h 18 min6,570 subs |
| Bortle 5Suburban | 32 min477 subs | 2 h 07 min1,905 subs | 8 h 28 min7,617 subs |
| Bortle 6Bright suburban | 42 min637 subs | 2 h 50 min2,547 subs | 11 h10,188 subs |
| Bortle 7Suburban / urban transition | 1 h 03 min943 subs | 4 h 11 min3,772 subs | 17 h15,087 subs |
| Bortle 8City | 1 h 35 min1,419 subs | 6 h 18 min5,674 subs | 25 h22,693 subs |
| Bortle 9Inner city | 2 h 42 min2,433 subs | 11 h9,729 subs | 43 h38,914 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 3 h 41 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 M61 is 6′ × 5.5′ across. The eQuinox 2 frames 0.76° × 0.57° at 1.33″ per pixel, so it fills 18% of the frame’s short side.
About the M61
A face-on barred spiral at the southern end of the Virgo cluster, with well-defined arms.
NGC 4303 · Galaxy in Virgo · magnitude 9.7 · 6′ × 5.5′ · best in Mar, Apr, May. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.
Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.
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 M61 from a eQuinox 2? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M61 with the ZWO Seestar S50: 3 h 07 min from Bortle 6
- M61 with the ZWO Seestar S50 Pro: 3 h 25 min from Bortle 6
- M61 with the ZWO Seestar S30: 3 h 17 min from Bortle 6
- M61 with the ZWO Seestar S30 Pro: 3 h 37 min from Bortle 6
- M61 with the DwarfLab DWARF 3: 4 h 32 min from Bortle 6
- M61 with the DwarfLab DWARF mini: 3 h 07 min from Bortle 6
- M61 with the DwarfLab Draco: 2 h 34 min from Bortle 6
- M61 with the DwarfLab DWARF II: 11 h from Bortle 6
- M61 with the Vaonis Vespera II: 3 h 07 min from Bortle 6
- M61 with the Vaonis Vespera Pro: 6 h 59 min from Bortle 6
- M61 with the Vaonis Vespera 3: 2 h 59 min from Bortle 6
- M61 with the Vaonis Vespera Pro 2: 6 h 40 min from Bortle 6
- M61 with the Unistellar Odyssey: 13 h from Bortle 6
- M61 with the Celestron Origin: 50 min from Bortle 6
- M61 with the Celestron Origin Mark II: 1 h 08 min from Bortle 6