How long to image the Sagittarius Star Cloud with the Vaonis Vespera Pro 2
From a Bortle 6 suburban sky, the Vaonis Vespera Pro 2 needs about 19 min (112 subs of 10 s) for a solid image of the Sagittarius Star Cloud. A quick look takes 5 min; a showpiece 1 h 15 min. Under a Bortle 3 rural sky the solid figure drops to 10 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 only just fits, at 91% of the short side.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 2 min14 subs | 9 min54 subs | 35 min213 subs |
| Bortle 2Typical dark site | 2 min14 subs | 9 min55 subs | 37 min220 subs |
| Bortle 3Rural | 2 min15 subs | 10 min59 subs | 39 min233 subs |
| Bortle 4Rural / suburban transition | 3 min17 subs | 11 min67 subs | 44 min267 subs |
| Bortle 5Suburban | 3 min20 subs | 13 min80 subs | 53 min319 subs |
| Bortle 6Bright suburban | 5 min28 subs | 19 min112 subs | 1 h 15 min448 subs |
| Bortle 7Suburban / urban transition | 7 min44 subs | 29 min174 subs | 1 h 56 min694 subs |
| Bortle 8City | 11 min68 subs | 45 min269 subs | 2 h 59 min1,076 subs |
| Bortle 9Inner city | 20 min119 subs | 1 h 19 min473 subs | 5 h 15 min1,890 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 24 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 Sagittarius Star Cloud is 90′ across. The Vespera Pro 2 frames 1.65° × 1.65° at 1.68″ per pixel, so it only just fits, at 91% of the short side. Centre it carefully: there is no room to crop back afterwards.
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 | 10 min59 subs | 13 min80 subs | 29 min174 subs |
| 20 s | 10 min30 subs | 12 min37 subs | 28 min84 subs |
| 30 s | 15 min30 subs | 15 min30 subs | 27 min55 subs |
About the Sagittarius Star Cloud
A window through the dust into the inner Milky Way, densely packed with stars. Short stacks are enough; it is stars, not nebulosity.
M24, IC 4715 · Star cloud in Sagittarius · magnitude 4.6 · 90′ · best in Jun, Jul, Aug. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Star clouds are dense fields of ordinary stars rather than nebulosity. Short subs, no filter, and a modest total keep the field from saturating while still showing the depth of the Milky Way.
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 Sagittarius Star Cloud 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
- Sagittarius Star Cloud with the ZWO Seestar S50: 9 min from Bortle 6
- Sagittarius Star Cloud with the ZWO Seestar S50 Pro: 10 min from Bortle 6
- Sagittarius Star Cloud with the ZWO Seestar S30: 9 min from Bortle 6
- Sagittarius Star Cloud with the ZWO Seestar S30 Pro: 10 min from Bortle 6
- Sagittarius Star Cloud with the DwarfLab DWARF 3: 13 min from Bortle 6
- Sagittarius Star Cloud with the DwarfLab DWARF mini: 9 min from Bortle 6
- Sagittarius Star Cloud with the DwarfLab Draco: 15 min from Bortle 6
- Sagittarius Star Cloud with the DwarfLab DWARF II: 29 min from Bortle 6
- Sagittarius Star Cloud with the Vaonis Vespera II: 9 min from Bortle 6
- Sagittarius Star Cloud with the Vaonis Vespera Pro: 20 min from Bortle 6
- Sagittarius Star Cloud with the Vaonis Vespera 3: 8 min from Bortle 6
- Sagittarius Star Cloud with the Unistellar eQuinox 2: 8 min from Bortle 6
- Sagittarius Star Cloud with the Unistellar Odyssey: 34 min from Bortle 6
- Sagittarius Star Cloud with the Celestron Origin: 5 min from Bortle 6
- Sagittarius Star Cloud with the Celestron Origin Mark II: 5 min from Bortle 6
All telescopes for the Sagittarius Star Cloud · All targets for the Vespera Pro 2