How long to image the M2 with the Vaonis Vespera 3
From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 10 min (60 subs of 10 s) for a solid image of the M2. A quick look takes 2 min; a showpiece 40 min. Under a Bortle 3 rural sky the solid figure drops to 5 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 18% 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 | 2 min10 subs | 5 min30 subs | 17 min104 subs |
| Bortle 2Typical dark site | 2 min10 subs | 5 min30 subs | 18 min108 subs |
| Bortle 3Rural | 2 min10 subs | 5 min30 subs | 19 min116 subs |
| Bortle 4Rural / suburban transition | 2 min10 subs | 6 min34 subs | 22 min135 subs |
| Bortle 5Suburban | 2 min11 subs | 7 min42 subs | 27 min165 subs |
| Bortle 6Bright suburban | 2 min15 subs | 10 min60 subs | 40 min238 subs |
| Bortle 7Suburban / urban transition | 4 min24 subs | 16 min95 subs | 1 h 03 min379 subs |
| Bortle 8City | 6 min38 subs | 25 min149 subs | 1 h 39 min596 subs |
| Bortle 9Inner city | 11 min67 subs | 44 min266 subs | 2 h 57 min1,061 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 13 min of run time. The Vespera 3’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 30WVaonis says an external bank extends sessions; 30 W PD as for the II and Pro.
- 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 3 →
How it frames
The M2 is 16′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it fills 18% 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 widens the field to 4.3° × 2.4°. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 5 min30 subs | 7 min42 subs | 16 min95 subs |
| 20 s | 10 min30 subs | 10 min30 subs | 15 min46 subs |
| 30 s | 15 min30 subs | 15 min30 subs | 15 min31 subs |
About the M2
A rich, compact globular in Aquarius. Resolves well at the edges even in a short stack.
NGC 7089 · Globular cluster in Aquarius · magnitude 6.5 · 16′ · 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 3
The 2026 Vespera: same 50 mm quadruplet class as the II on an 8 MP IMX585, with a 24 MP mosaic mode and 11 hours of battery. Per pixel it behaves like a Seestar S50 Pro without the built-in dual-band filter.
10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only; CovalENS mosaic widens the field to 4.3° × 2.4°. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar. The new optical baffle is not a substitute for a CLS filter.
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 M2 from a Vespera 3? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M2 with the ZWO Seestar S50: 10 min from Bortle 6
- M2 with the ZWO Seestar S50 Pro: 11 min from Bortle 6
- M2 with the ZWO Seestar S30: 11 min from Bortle 6
- M2 with the ZWO Seestar S30 Pro: 12 min from Bortle 6
- M2 with the DwarfLab DWARF 3: 15 min from Bortle 6
- M2 with the DwarfLab DWARF mini: 10 min from Bortle 6
- M2 with the DwarfLab Draco: 15 min from Bortle 6
- M2 with the DwarfLab DWARF II: 34 min from Bortle 6
- M2 with the Vaonis Vespera II: 10 min from Bortle 6
- M2 with the Vaonis Vespera Pro: 23 min from Bortle 6
- M2 with the Vaonis Vespera Pro 2: 22 min from Bortle 6
- M2 with the Unistellar eQuinox 2: 9 min from Bortle 6
- M2 with the Unistellar Odyssey: 40 min from Bortle 6
- M2 with the Celestron Origin: 5 min from Bortle 6
- M2 with the Celestron Origin Mark II: 5 min from Bortle 6