How long to image the M72 with the Vaonis Vespera Pro
From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 2 h 39 min (956 subs of 10 s) for a solid image of the M72. A quick look takes 40 min; a showpiece 11 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 13 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 6% 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 | 16 min97 subs | 1 h 04 min387 subs | 4 h 18 min1,546 subs |
| Bortle 2Typical dark site | 17 min101 subs | 1 h 07 min404 subs | 4 h 29 min1,616 subs |
| Bortle 3Rural | 18 min110 subs | 1 h 13 min438 subs | 4 h 51 min1,749 subs |
| Bortle 4Rural / suburban transition | 22 min130 subs | 1 h 26 min518 subs | 5 h 45 min2,069 subs |
| Bortle 5Suburban | 27 min162 subs | 1 h 47 min645 subs | 7 h 09 min2,577 subs |
| Bortle 6Bright suburban | 40 min239 subs | 2 h 39 min956 subs | 11 h3,824 subs |
| Bortle 7Suburban / urban transition | 1 h 05 min388 subs | 4 h 18 min1,550 subs | 17 h6,200 subs |
| Bortle 8City | 1 h 43 min618 subs | 6 h 52 min2,472 subs | 27 h9,888 subs |
| Bortle 9Inner city | 3 h 05 min1,110 subs | 12 h4,439 subs | 49 h17,755 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 3 h 27 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.)
- 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.
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Everything that fits the Vespera Pro →
How it frames
The M72 is 6′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 6% 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 13 min438 subs | 1 h 47 min645 subs | 4 h 18 min1,550 subs |
| 20 s | 1 h 02 min186 subs | 1 h 36 min290 subs | 4 h 07 min743 subs |
| 30 s | 58 min117 subs | 1 h 33 min186 subs | 4 h 04 min488 subs |
About the M72
A faint, distant globular in Aquarius. Among the harder Messier globulars.
NGC 6981 · Globular cluster in Aquarius · magnitude 9.3 · 6′ · best in Jul, Aug, Sep. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Globular clusters are point sources packed tight, so they come quickly: the core resolves into stars within a handful of minutes on any smart scope. More time deepens the halo and pulls in the faint outer members. Use short subs so the core does not saturate into a white blob, and no filter.
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 M72 from a Vespera Pro? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M72 with the ZWO Seestar S50: 1 h 11 min from Bortle 6
- M72 with the ZWO Seestar S50 Pro: 1 h 18 min from Bortle 6
- M72 with the ZWO Seestar S30: 1 h 15 min from Bortle 6
- M72 with the ZWO Seestar S30 Pro: 1 h 23 min from Bortle 6
- M72 with the DwarfLab DWARF 3: 1 h 44 min from Bortle 6
- M72 with the DwarfLab DWARF mini: 1 h 11 min from Bortle 6
- M72 with the DwarfLab Draco: 59 min from Bortle 6
- M72 with the DwarfLab DWARF II: 4 h 02 min from Bortle 6
- M72 with the Vaonis Vespera II: 1 h 11 min from Bortle 6
- M72 with the Vaonis Vespera 3: 1 h 08 min from Bortle 6
- M72 with the Vaonis Vespera Pro 2: 2 h 32 min from Bortle 6
- M72 with the Unistellar eQuinox 2: 1 h 04 min from Bortle 6
- M72 with the Unistellar Odyssey: 4 h 51 min from Bortle 6
- M72 with the Celestron Origin: 19 min from Bortle 6
- M72 with the Celestron Origin Mark II: 26 min from Bortle 6
All telescopes for the M72 · All targets for the Vespera Pro