How long to image the Bow-Tie Nebula with the Vaonis Vespera Pro 2
From a Bortle 6 suburban sky, the Vaonis Vespera Pro 2 needs about 58 min (350 subs of 10 s) for a solid image of the Bow-Tie Nebula. A quick look takes 15 min; a showpiece 3 h 53 min. Under a Bortle 3 rural sky the solid figure drops to 29 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 is small in the frame, about 29 pixels across.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 7 min40 subs | 26 min158 subs | 1 h 45 min631 subs |
| Bortle 2Typical dark site | 7 min41 subs | 27 min164 subs | 1 h 49 min654 subs |
| Bortle 3Rural | 7 min44 subs | 29 min175 subs | 1 h 56 min699 subs |
| Bortle 4Rural / suburban transition | 8 min51 subs | 34 min202 subs | 2 h 14 min807 subs |
| Bortle 5Suburban | 10 min62 subs | 41 min245 subs | 2 h 43 min978 subs |
| Bortle 6Bright suburban | 15 min88 subs | 58 min350 subs | 3 h 53 min1,398 subs |
| Bortle 7Suburban / urban transition | 23 min138 subs | 1 h 32 min550 subs | 6 h 06 min2,197 subs |
| Bortle 8City | 36 min215 subs | 2 h 23 min860 subs | 9 h 33 min3,438 subs |
| Bortle 9Inner city | 1 h 03 min381 subs | 4 h 14 min1,522 subs | 17 h6,086 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 16 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.)
- 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.
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How it frames
The Bow-Tie Nebula is 0.8′ × 0.6′ across. The Vespera Pro 2 frames 1.65° × 1.65° at 1.68″ per pixel, so it is small in the frame, about 29 pixels across. It is worth doing, but the result is a crop rather than a full frame; a longer focal length would resolve more of it.
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 | 29 min175 subs | 41 min245 subs | 1 h 32 min550 subs |
| 20 s | 26 min77 subs | 37 min112 subs | 1 h 28 min265 subs |
| 30 s | 24 min49 subs | 36 min73 subs | 1 h 27 min174 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| No filter | 29 min175 subs | 41 min245 subs | 1 h 32 min550 subs |
| dual-band (Dual Band filter), clip-on | 39 min232 subs | 42 min253 subs | 58 min347 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 Bow-Tie Nebula
A red-tinged planetary near the pole with a bright central star. Small; dual-band brings out the bow.
NGC 40, Caldwell 2 · Planetary nebula in Cepheus · magnitude 11.6 · 0.8′ × 0.6′ · best in Sep, Oct, Nov. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Planetary nebulae are small but intensely bright per pixel in OIII and H-alpha, so they respond very well to a dual-band filter and do not need much time for the main shell. The faint outer halos most of them have are a different proposition and need hours. Keep subs short if the central region saturates.
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 Bow-Tie 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
- Bow-Tie Nebula with the ZWO Seestar S50: 21 min from Bortle 6
- Bow-Tie Nebula with the ZWO Seestar S50 Pro: 23 min from Bortle 6
- Bow-Tie Nebula with the ZWO Seestar S30: 23 min from Bortle 6
- Bow-Tie Nebula with the ZWO Seestar S30 Pro: 25 min from Bortle 6
- Bow-Tie Nebula with the DwarfLab DWARF 3: 28 min from Bortle 6
- Bow-Tie Nebula with the DwarfLab DWARF mini: 21 min from Bortle 6
- Bow-Tie Nebula with the DwarfLab Draco: 17 min from Bortle 6
- Bow-Tie Nebula with the DwarfLab DWARF II: 1 h 32 min from Bortle 6
- Bow-Tie Nebula with the Vaonis Vespera II: 27 min from Bortle 6
- Bow-Tie Nebula with the Vaonis Vespera Pro: 1 h 01 min from Bortle 6
- Bow-Tie Nebula with the Vaonis Vespera 3: 26 min from Bortle 6
- Bow-Tie Nebula with the Unistellar eQuinox 2: 24 min from Bortle 6
- Bow-Tie Nebula with the Unistellar Odyssey: 1 h 48 min from Bortle 6
- Bow-Tie Nebula with the Celestron Origin: 7 min from Bortle 6
- Bow-Tie Nebula with the Celestron Origin Mark II: 10 min from Bortle 6
All telescopes for the Bow-Tie Nebula · All targets for the Vespera Pro 2