How long to image the M78 with the Vaonis Vespera Pro
From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 2 h 20 min (840 subs of 10 s) for a solid image of the M78. A quick look takes 35 min; a showpiece 9 h 20 min. Under a Bortle 3 rural sky the solid figure drops to 1 h 04 min. 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 | 14 min85 subs | 56 min338 subs | 3 h 45 min1,351 subs |
| Bortle 2Typical dark site | 15 min89 subs | 59 min354 subs | 3 h 55 min1,413 subs |
| Bortle 3Rural | 16 min96 subs | 1 h 04 min383 subs | 4 h 15 min1,530 subs |
| Bortle 4Rural / suburban transition | 19 min114 subs | 1 h 15 min453 subs | 5 h 02 min1,812 subs |
| Bortle 5Suburban | 24 min142 subs | 1 h 34 min565 subs | 6 h 17 min2,260 subs |
| Bortle 6Bright suburban | 35 min210 subs | 2 h 20 min840 subs | 9 h 20 min3,360 subs |
| Bortle 7Suburban / urban transition | 57 min341 subs | 3 h 47 min1,364 subs | 15 h5,455 subs |
| Bortle 8City | 1 h 31 min545 subs | 6 h 03 min2,177 subs | 24 h8,708 subs |
| Bortle 9Inner city | 2 h 43 min978 subs | 11 h3,912 subs | 43 h15,645 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 3 h 02 min of run time. The Vespera Pro’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 30WExtends the 11 h battery; 30 W PD per Vaonis.
- 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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How it frames
The M78 is 8′ × 6′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ 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, no EQ mode. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 1 h 04 min383 subs | 1 h 34 min565 subs | 3 h 47 min1,364 subs |
| 20 s | 54 min163 subs | 1 h 25 min254 subs | 3 h 38 min654 subs |
| 30 s | 51 min102 subs | 1 h 21 min163 subs | 3 h 34 min429 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
The square-sensor Vespera with 2 µm pixels. Higher resolution than the II, and correspondingly slower per pixel: expect around double the time for the same per-pixel SNR. Run-out in 2026 and replaced by the Vespera Pro 2.
10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only, no EQ mode. 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? 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 3: 1 h from Bortle 6
- M78 with the Vaonis Vespera Pro 2: 2 h 13 min 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