How long to image the M72 with the Vaonis Vespera Pro 2
From a Bortle 6 suburban sky, the Vaonis Vespera Pro 2 needs about 2 h 32 min (912 subs of 10 s) for a solid image of the M72. A quick look takes 38 min; a showpiece 10 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 09 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 | 15 min92 subs | 1 h 01 min365 subs | 4 h 03 min1,459 subs |
| Bortle 2Typical dark site | 16 min96 subs | 1 h 04 min382 subs | 4 h 14 min1,526 subs |
| Bortle 3Rural | 17 min104 subs | 1 h 09 min414 subs | 4 h 35 min1,653 subs |
| Bortle 4Rural / suburban transition | 20 min123 subs | 1 h 22 min491 subs | 5 h 27 min1,961 subs |
| Bortle 5Suburban | 26 min154 subs | 1 h 42 min613 subs | 6 h 48 min2,449 subs |
| Bortle 6Bright suburban | 38 min228 subs | 2 h 32 min912 subs | 10 h3,647 subs |
| Bortle 7Suburban / urban transition | 1 h 02 min371 subs | 4 h 07 min1,482 subs | 16 h5,928 subs |
| Bortle 8City | 1 h 39 min592 subs | 6 h 35 min2,368 subs | 26 h9,471 subs |
| Bortle 9Inner city | 2 h 57 min1,065 subs | 12 h4,257 subs | 47 h17,025 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 3 h 18 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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Everything that fits the Vespera Pro 2 →
How it frames
The M72 is 6′ across. The Vespera Pro 2 frames 1.65° × 1.65° at 1.68″ 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; 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 | 1 h 09 min414 subs | 1 h 42 min613 subs | 4 h 07 min1,482 subs |
| 20 s | 59 min177 subs | 1 h 32 min276 subs | 3 h 57 min711 subs |
| 30 s | 55 min111 subs | 1 h 29 min178 subs | 3 h 54 min468 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 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 M72 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
- 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 Pro: 2 h 39 min from Bortle 6
- M72 with the Vaonis Vespera 3: 1 h 08 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 2