How long to image the M54 with the Vaonis Vespera Pro
From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 1 h 03 min (381 subs of 10 s) for a solid image of the M54. A quick look takes 16 min; a showpiece 4 h 14 min. Under a Bortle 3 rural sky the solid figure drops to 30 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 12% 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 | 7 min40 subs | 27 min160 subs | 1 h 47 min640 subs |
| Bortle 2Typical dark site | 7 min42 subs | 28 min167 subs | 1 h 51 min667 subs |
| Bortle 3Rural | 7 min45 subs | 30 min180 subs | 2 h718 subs |
| Bortle 4Rural / suburban transition | 9 min53 subs | 35 min211 subs | 2 h 20 min842 subs |
| Bortle 5Suburban | 11 min65 subs | 43 min260 subs | 2 h 53 min1,040 subs |
| Bortle 6Bright suburban | 16 min96 subs | 1 h 03 min381 subs | 4 h 14 min1,523 subs |
| Bortle 7Suburban / urban transition | 25 min153 subs | 1 h 42 min612 subs | 6 h 47 min2,445 subs |
| Bortle 8City | 40 min243 subs | 2 h 41 min969 subs | 11 h3,876 subs |
| Bortle 9Inner city | 1 h 12 min434 subs | 4 h 49 min1,733 subs | 19 h6,929 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 22 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.
Affiliate links: the retailer pays us a small commission and you pay the same price. These are search links to the named product, not endorsements of a particular listing; check the listing matches your model.
Everything that fits the Vespera Pro →
How it frames
The M54 is 12′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 12% 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 | 30 min180 subs | 43 min260 subs | 1 h 42 min612 subs |
| 20 s | 26 min78 subs | 39 min118 subs | 1 h 38 min293 subs |
| 30 s | 24 min49 subs | 38 min76 subs | 1 h 36 min193 subs |
About the M54
A globular that actually belongs to the Sagittarius Dwarf galaxy being eaten by the Milky Way. Low from the north.
NGC 6715 · Globular cluster in Sagittarius · magnitude 7.6 · 12′ · best in Jun, Jul, Aug. 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 M54 from a Vespera Pro? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M54 with the ZWO Seestar S50: 28 min from Bortle 6
- M54 with the ZWO Seestar S50 Pro: 31 min from Bortle 6
- M54 with the ZWO Seestar S30: 30 min from Bortle 6
- M54 with the ZWO Seestar S30 Pro: 33 min from Bortle 6
- M54 with the DwarfLab DWARF 3: 42 min from Bortle 6
- M54 with the DwarfLab DWARF mini: 28 min from Bortle 6
- M54 with the DwarfLab Draco: 23 min from Bortle 6
- M54 with the DwarfLab DWARF II: 1 h 36 min from Bortle 6
- M54 with the Vaonis Vespera II: 28 min from Bortle 6
- M54 with the Vaonis Vespera 3: 27 min from Bortle 6
- M54 with the Vaonis Vespera Pro 2: 1 h 01 min from Bortle 6
- M54 with the Unistellar eQuinox 2: 25 min from Bortle 6
- M54 with the Unistellar Odyssey: 1 h 55 min from Bortle 6
- M54 with the Celestron Origin: 8 min from Bortle 6
- M54 with the Celestron Origin Mark II: 10 min from Bortle 6
All telescopes for the M54 · All targets for the Vespera Pro