How long to image the M3 with the Vaonis Vespera 3
From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 9 min (56 subs of 10 s) for a solid image of the M3. A quick look takes 2 min; a showpiece 37 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 20% 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 | 16 min98 subs |
| Bortle 2Typical dark site | 2 min10 subs | 5 min30 subs | 17 min102 subs |
| Bortle 3Rural | 2 min10 subs | 5 min30 subs | 18 min109 subs |
| Bortle 4Rural / suburban transition | 2 min10 subs | 5 min32 subs | 21 min126 subs |
| Bortle 5Suburban | 2 min10 subs | 6 min39 subs | 26 min154 subs |
| Bortle 6Bright suburban | 2 min14 subs | 9 min56 subs | 37 min222 subs |
| Bortle 7Suburban / urban transition | 4 min22 subs | 15 min88 subs | 58 min351 subs |
| Bortle 8City | 6 min35 subs | 23 min138 subs | 1 h 32 min552 subs |
| Bortle 9Inner city | 10 min62 subs | 41 min245 subs | 2 h 43 min980 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 12 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 M3 is 18′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it fills 20% 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 | 6 min39 subs | 15 min88 subs |
| 20 s | 10 min30 subs | 10 min30 subs | 14 min43 subs |
| 30 s | 15 min30 subs | 15 min30 subs | 15 min30 subs |
About the M3
One of the finest northern globulars, half a million stars in a tight ball. A spring showpiece that needs little time.
NGC 5272 · Globular cluster in Canes Venatici · magnitude 6.2 · 18′ · best in Mar, Apr, May. 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 M3 from a Vespera 3? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M3 with the ZWO Seestar S50: 10 min from Bortle 6
- M3 with the ZWO Seestar S50 Pro: 11 min from Bortle 6
- M3 with the ZWO Seestar S30: 10 min from Bortle 6
- M3 with the ZWO Seestar S30 Pro: 11 min from Bortle 6
- M3 with the DwarfLab DWARF 3: 14 min from Bortle 6
- M3 with the DwarfLab DWARF mini: 10 min from Bortle 6
- M3 with the DwarfLab Draco: 15 min from Bortle 6
- M3 with the DwarfLab DWARF II: 32 min from Bortle 6
- M3 with the Vaonis Vespera II: 10 min from Bortle 6
- M3 with the Vaonis Vespera Pro: 21 min from Bortle 6
- M3 with the Vaonis Vespera Pro 2: 20 min from Bortle 6
- M3 with the Unistellar eQuinox 2: 8 min from Bortle 6
- M3 with the Unistellar Odyssey: 37 min from Bortle 6
- M3 with the Celestron Origin: 5 min from Bortle 6
- M3 with the Celestron Origin Mark II: 5 min from Bortle 6