How long to image the De Mairan's Nebula with the Vaonis Vespera Pro 2
From a Bortle 6 suburban sky, the Vaonis Vespera Pro 2 needs about 1 h 41 min (604 subs of 10 s) for a solid image of the De Mairan's Nebula. A quick look takes 25 min; a showpiece 6 h 42 min. Under a Bortle 3 rural sky the solid figure drops to 44 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 20% 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 | 10 min58 subs | 39 min232 subs | 2 h 35 min928 subs |
| Bortle 2Typical dark site | 10 min61 subs | 41 min244 subs | 2 h 42 min974 subs |
| Bortle 3Rural | 11 min67 subs | 44 min265 subs | 2 h 57 min1,060 subs |
| Bortle 4Rural / suburban transition | 13 min80 subs | 53 min318 subs | 3 h 31 min1,269 subs |
| Bortle 5Suburban | 17 min101 subs | 1 h 07 min401 subs | 4 h 27 min1,601 subs |
| Bortle 6Bright suburban | 25 min151 subs | 1 h 41 min604 subs | 6 h 42 min2,415 subs |
| Bortle 7Suburban / urban transition | 41 min248 subs | 2 h 45 min992 subs | 11 h3,966 subs |
| Bortle 8City | 1 h 06 min399 subs | 4 h 26 min1,594 subs | 18 h6,375 subs |
| Bortle 9Inner city | 2 h720 subs | 8 h2,878 subs | 32 h11,511 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 2 h 11 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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How it frames
The De Mairan's Nebula is 20′ × 15′ across. The Vespera Pro 2 frames 1.65° × 1.65° at 1.68″ per pixel, so it fills 20% 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 | 44 min265 subs | 1 h 07 min401 subs | 2 h 45 min992 subs |
| 20 s | 37 min112 subs | 1 h180 subs | 2 h 38 min476 subs |
| 30 s | 35 min71 subs | 58 min116 subs | 2 h 36 min313 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| No filter | 44 min265 subs | 1 h 07 min401 subs | 2 h 45 min992 subs |
| dual-band (Dual Band filter), clip-on | 57 min344 subs | 1 h 04 min386 subs | 1 h 34 min567 subs |
The Vespera Pro 2 has no built-in dual-band filter. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar. On an emission target like this it is the single biggest upgrade you can make.
About the De Mairan's Nebula
The comma-shaped nebula north of the Orion Nebula's core, split from it by a dark lane. Always in the same frame as M42.
M43, NGC 1982 · Emission nebula in Orion · magnitude 9.0 · 20′ × 15′ · best in Nov, Dec, Jan. 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 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 De Mairan's Nebula 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
- De Mairan's Nebula with the ZWO Seestar S50: 32 min from Bortle 6
- De Mairan's Nebula with the ZWO Seestar S50 Pro: 35 min from Bortle 6
- De Mairan's Nebula with the ZWO Seestar S30: 36 min from Bortle 6
- De Mairan's Nebula with the ZWO Seestar S30 Pro: 38 min from Bortle 6
- De Mairan's Nebula with the DwarfLab DWARF 3: 40 min from Bortle 6
- De Mairan's Nebula with the DwarfLab DWARF mini: 31 min from Bortle 6
- De Mairan's Nebula with the DwarfLab Draco: 25 min from Bortle 6
- De Mairan's Nebula with the DwarfLab DWARF II: 2 h 41 min from Bortle 6
- De Mairan's Nebula with the Vaonis Vespera II: 47 min from Bortle 6
- De Mairan's Nebula with the Vaonis Vespera Pro: 1 h 46 min from Bortle 6
- De Mairan's Nebula with the Vaonis Vespera 3: 45 min from Bortle 6
- De Mairan's Nebula with the Unistellar eQuinox 2: 42 min from Bortle 6
- De Mairan's Nebula with the Unistellar Odyssey: 3 h 15 min from Bortle 6
- De Mairan's Nebula with the Celestron Origin: 13 min from Bortle 6
- De Mairan's Nebula with the Celestron Origin Mark II: 17 min from Bortle 6
All telescopes for the De Mairan's Nebula · All targets for the Vespera Pro 2