How long to image the Sagittarius Star Cloud with the Vaonis Vespera II
From a Bortle 6 suburban sky, the Vaonis Vespera II needs about 9 min (53 subs of 10 s) for a solid image of the Sagittarius Star Cloud. A quick look takes 2 min; a showpiece 35 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 is just over the frame at 1.0×.
| 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 min96 subs |
| Bortle 2Typical dark site | 2 min10 subs | 5 min30 subs | 16 min99 subs |
| Bortle 3Rural | 2 min10 subs | 5 min30 subs | 18 min106 subs |
| Bortle 4Rural / suburban transition | 2 min10 subs | 5 min31 subs | 20 min122 subs |
| Bortle 5Suburban | 2 min10 subs | 6 min37 subs | 25 min148 subs |
| Bortle 6Bright suburban | 2 min14 subs | 9 min53 subs | 35 min212 subs |
| Bortle 7Suburban / urban transition | 3 min21 subs | 14 min84 subs | 56 min334 subs |
| Bortle 8City | 5 min33 subs | 22 min131 subs | 1 h 27 min523 subs |
| Bortle 9Inner city | 10 min58 subs | 39 min232 subs | 2 h 34 min926 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 11 min of run time. The Vespera II’s battery (rated about 4 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 30WOnly four hours inside; Vaonis specifies a 30 W PD source. C-to-C cable not included.
- Vaonis Vespera hygrometer sensorTriggers the built-in demister automatically; the correct dew accessory for the II.
- 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 II →
How it frames
The Sagittarius Star Cloud is 90′ across. The Vespera II frames 2.55° × 1.44° at 2.39″ per pixel, so it is just over the frame at 1.0×. Point at the part you want; the edges will fall outside the frame.
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 | 5 min30 subs | 6 min37 subs | 14 min84 subs |
| 20 s | 10 min30 subs | 10 min30 subs | 13 min41 subs |
| 30 s | 15 min30 subs | 15 min30 subs | 15 min30 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 II
A 50 mm quadruplet on an 8 MP sensor with Vaonis’s mosaic mode for wide fields. Same optics class as the Seestar S50, four times the pixels.
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; the app detects which is fitted.
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 II? 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 Pro: 20 min from Bortle 6
- Sagittarius Star Cloud with the Vaonis Vespera 3: 8 min from Bortle 6
- Sagittarius Star Cloud with the Vaonis Vespera Pro 2: 19 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 II