How long to image the M78 with the Vaonis Vespera Pro 2
From a Bortle 6 suburban sky, the Vaonis Vespera Pro 2 needs about 2 h 13 min (801 subs of 10 s) for a solid image of the M78. A quick look takes 33 min; a showpiece 8 h 54 min. Under a Bortle 3 rural sky the solid figure drops to 1 h. At Bortle 6 the limit is skyglow, so a darker site or a filter helps more than longer subs. In this scope's field it fills 8% 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 | 13 min80 subs | 53 min319 subs | 3 h 32 min1,275 subs |
| Bortle 2Typical dark site | 14 min84 subs | 56 min334 subs | 3 h 42 min1,334 subs |
| Bortle 3Rural | 15 min91 subs | 1 h362 subs | 4 h 01 min1,446 subs |
| Bortle 4Rural / suburban transition | 18 min108 subs | 1 h 12 min430 subs | 4 h 46 min1,718 subs |
| Bortle 5Suburban | 22 min135 subs | 1 h 29 min537 subs | 5 h 58 min2,148 subs |
| Bortle 6Bright suburban | 33 min201 subs | 2 h 13 min801 subs | 8 h 54 min3,204 subs |
| Bortle 7Suburban / urban transition | 54 min326 subs | 3 h 37 min1,304 subs | 14 h5,216 subs |
| Bortle 8City | 1 h 27 min522 subs | 5 h 47 min2,085 subs | 23 h8,340 subs |
| Bortle 9Inner city | 2 h 36 min938 subs | 10 h3,751 subs | 42 h15,003 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 2 h 54 min of run time. The Vespera Pro 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, and 30% off the battery for a December night.)
- USB-C PD power bank 20000mAh 30WExternal bank extends the 11 h battery.
- 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 Vespera Pro 2 →
How it frames
The M78 is 8′ × 6′ across. The Vespera Pro 2 frames 1.65° × 1.65° at 1.68″ per pixel, so it fills 8% of the frame’s short side.
Longer subs
10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only; CovalENS mosaic gives 3.2° × 3.2° at 50 MP. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 1 h362 subs | 1 h 29 min537 subs | 3 h 37 min1,304 subs |
| 20 s | 51 min155 subs | 1 h 21 min242 subs | 3 h 28 min626 subs |
| 30 s | 48 min97 subs | 1 h 18 min156 subs | 3 h 26 min412 subs |
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 Vaonis Vespera Pro 2
The square-sensor 2026 Vespera with 2 µm pixels. Sharper than the Vespera 3 on small targets and correspondingly slower per pixel; the 12.5 MP square frame suits galaxies and planetaries.
10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only; CovalENS mosaic gives 3.2° × 3.2° at 50 MP. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar.
Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 10 s and 30 s subs is small; from a rural site it can halve the total time, especially with a dual-band filter in place.
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 Vespera Pro 2? 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 Unistellar eQuinox 2: 56 min from Bortle 6
- M78 with the Unistellar Odyssey: 4 h 16 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
All telescopes for the M78 · All targets for the Vespera Pro 2