How long to image the Monkey Head Nebula with the Vaonis Vespera II
From a Bortle 6 suburban sky, the Vaonis Vespera II needs about 2 h 42 min (971 subs of 10 s) for a solid image of the Monkey Head Nebula. A quick look takes 40 min; a showpiece 11 h. 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 46% 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 min76 subs | 50 min303 subs | 3 h 22 min1,210 subs |
| Bortle 2Typical dark site | 13 min81 subs | 54 min323 subs | 3 h 35 min1,292 subs |
| Bortle 3Rural | 15 min91 subs | 1 h362 subs | 4 h 01 min1,447 subs |
| Bortle 4Rural / suburban transition | 19 min114 subs | 1 h 16 min456 subs | 5 h 04 min1,824 subs |
| Bortle 5Suburban | 25 min152 subs | 1 h 41 min605 subs | 6 h 43 min2,420 subs |
| Bortle 6Bright suburban | 40 min243 subs | 2 h 42 min971 subs | 11 h3,884 subs |
| Bortle 7Suburban / urban transition | 1 h 10 min418 subs | 4 h 38 min1,669 subs | 19 h6,673 subs |
| Bortle 8City | 1 h 55 min688 subs | 7 h 38 min2,751 subs | 31 h11,004 subs |
| Bortle 9Inner city | 3 h 31 min1,265 subs | 14 h5,060 subs | 56 h20,239 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 3 h 30 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 January 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 Monkey Head Nebula is 40′ × 30′ across. The Vespera II frames 2.55° × 1.44° at 2.39″ per pixel, so it fills 46% 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 h362 subs | 1 h 41 min605 subs | 4 h 38 min1,669 subs |
| 20 s | 51 min153 subs | 1 h 31 min274 subs | 4 h 29 min806 subs |
| 30 s | 48 min96 subs | 1 h 28 min177 subs | 4 h 25 min531 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| No filter | 1 h362 subs | 1 h 41 min605 subs | 4 h 38 min1,669 subs |
| dual-band (Dual Band filter), clip-on | 1 h 10 min420 subs | 1 h 22 min495 subs | 2 h 17 min820 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 Monkey Head Nebula
A round emission cloud on the Orion-Gemini border with a profile like a monkey's face. Moderately bright, good with dual-band.
NGC 2174, Sh2-252 · Emission nebula in Orion · magnitude 6.8 · 40′ × 30′ · best in Dec, Jan, Feb. 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 Monkey Head 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
- Monkey Head Nebula with the ZWO Seestar S50: 1 h 41 min from Bortle 6
- Monkey Head Nebula with the ZWO Seestar S50 Pro: 1 h 53 min from Bortle 6
- Monkey Head Nebula with the ZWO Seestar S30: 1 h 58 min from Bortle 6
- Monkey Head Nebula with the ZWO Seestar S30 Pro: 2 h 02 min from Bortle 6
- Monkey Head Nebula with the DwarfLab DWARF 3: 2 h 05 min from Bortle 6
- Monkey Head Nebula with the DwarfLab DWARF mini: 1 h 40 min from Bortle 6
- Monkey Head Nebula with the DwarfLab Draco: 1 h 20 min from Bortle 6
- Monkey Head Nebula with the DwarfLab DWARF II: 9 h 16 min from Bortle 6
- Monkey Head Nebula with the Vaonis Vespera Pro: 6 h 03 min from Bortle 6
- Monkey Head Nebula with the Vaonis Vespera 3: 2 h 35 min from Bortle 6
- Monkey Head Nebula with the Vaonis Vespera Pro 2: 5 h 46 min from Bortle 6
- Monkey Head Nebula with the Unistellar eQuinox 2: 2 h 28 min from Bortle 6
- Monkey Head Nebula with the Unistellar Odyssey: 11 h from Bortle 6
- Monkey Head Nebula with the Celestron Origin: 43 min from Bortle 6
- Monkey Head Nebula with the Celestron Origin Mark II: 59 min from Bortle 6
All telescopes for the Monkey Head Nebula · All targets for the Vespera II