How long to image the Horsehead Nebula with the Vaonis Vespera II
From a Bortle 6 suburban sky, the Vaonis Vespera II needs about 3 h 13 min (1,161 subs of 10 s) for a solid image of the Horsehead Nebula. A quick look takes 48 min; a showpiece 13 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 11 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 70% 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 | 15 min90 subs | 59 min357 subs | 3 h 58 min1,427 subs |
| Bortle 2Typical dark site | 16 min96 subs | 1 h 04 min382 subs | 4 h 14 min1,526 subs |
| Bortle 3Rural | 18 min108 subs | 1 h 11 min429 subs | 4 h 45 min1,713 subs |
| Bortle 4Rural / suburban transition | 23 min136 subs | 1 h 30 min542 subs | 6 h 01 min2,165 subs |
| Bortle 5Suburban | 30 min181 subs | 2 h721 subs | 8 h2,883 subs |
| Bortle 6Bright suburban | 48 min291 subs | 3 h 13 min1,161 subs | 13 h4,642 subs |
| Bortle 7Suburban / urban transition | 1 h 23 min500 subs | 5 h 33 min1,999 subs | 22 h7,996 subs |
| Bortle 8City | 2 h 18 min826 subs | 9 h 10 min3,301 subs | 37 h13,202 subs |
| Bortle 9Inner city | 4 h 13 min1,520 subs | 17 h6,077 subs | 68 h24,306 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 4 h 11 min of run time. The Vespera II’s battery is rated at about 4 h, less near freezing, so the session needs an external power bank. (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 30WOnly four hours inside; Vaonis specifies a 30 W PD source. C-to-C cable not included.
- Vaonis Vespera hygrometer sensorTriggers the built-in demister automatically; the correct dew accessory for the II.
- 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 II →
How it frames
The Horsehead Nebula is 60′ × 10′ across. The Vespera II frames 2.55° × 1.44° at 2.39″ per pixel, so it fills 70% 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 11 min429 subs | 2 h721 subs | 5 h 33 min1,999 subs |
| 20 s | 1 h180 subs | 1 h 49 min327 subs | 5 h 22 min966 subs |
| 30 s | 56 min113 subs | 1 h 45 min210 subs | 5 h 18 min636 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| No filter | 1 h 11 min429 subs | 2 h721 subs | 5 h 33 min1,999 subs |
| dual-band (Dual Band filter), clip-on | 1 h 23 min496 subs | 1 h 37 min585 subs | 2 h 43 min976 subs |
The Vespera II has no built-in dual-band filter. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar; the app detects which is fitted. On an emission target like this it is the single biggest upgrade you can make.
About the Horsehead Nebula
The horse's head is a dark cloud in front of the glowing IC 434 ribbon. You image the ribbon; the head is what is missing. Dual-band, and expect a few hours from suburbia.
IC 434, Barnard 33 · Emission nebula in Orion · magnitude 7.3 · 60′ × 10′ · 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 II
A 50 mm quadruplet on an 8 MP sensor with Vaonis’s mosaic mode for wide fields. Same optics class as the Seestar S50, four times the pixels.
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; the app detects which is fitted.
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 Horsehead Nebula from a Vespera II? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Horsehead Nebula with the ZWO Seestar S50: 2 h from Bortle 6
- Horsehead Nebula with the ZWO Seestar S50 Pro: 2 h 15 min from Bortle 6
- Horsehead Nebula with the ZWO Seestar S30: 2 h 20 min from Bortle 6
- Horsehead Nebula with the ZWO Seestar S30 Pro: 2 h 25 min from Bortle 6
- Horsehead Nebula with the DwarfLab DWARF 3: 2 h 28 min from Bortle 6
- Horsehead Nebula with the DwarfLab DWARF mini: 1 h 58 min from Bortle 6
- Horsehead Nebula with the DwarfLab Draco: 1 h 35 min from Bortle 6
- Horsehead Nebula with the DwarfLab DWARF II: 11 h from Bortle 6
- Horsehead Nebula with the Vaonis Vespera Pro: 7 h 14 min from Bortle 6
- Horsehead Nebula with the Vaonis Vespera 3: 3 h 05 min from Bortle 6
- Horsehead Nebula with the Vaonis Vespera Pro 2: 6 h 53 min from Bortle 6
- Horsehead Nebula with the Unistellar eQuinox 2: 2 h 57 min from Bortle 6
- Horsehead Nebula with the Unistellar Odyssey: 14 h from Bortle 6
- Horsehead Nebula with the Celestron Origin: 51 min from Bortle 6
- Horsehead Nebula with the Celestron Origin Mark II: 1 h 10 min from Bortle 6
All telescopes for the Horsehead Nebula · All targets for the Vespera II