How long to image the Sagittarius Star Cloud with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 34 min (510 subs of 4 s) for a solid image of the Sagittarius Star Cloud. A quick look takes 8 min; a showpiece 2 h 16 min. Under a Bortle 3 rural sky the solid figure drops to 24 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it is 2.7× wider than the frame.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 6 min87 subs | 23 min345 subs | 1 h 32 min1,377 subs |
| Bortle 2Typical dark site | 6 min88 subs | 23 min350 subs | 1 h 33 min1,397 subs |
| Bortle 3Rural | 6 min90 subs | 24 min359 subs | 1 h 36 min1,435 subs |
| Bortle 4Rural / suburban transition | 6 min96 subs | 25 min382 subs | 1 h 42 min1,528 subs |
| Bortle 5Suburban | 7 min105 subs | 28 min419 subs | 1 h 52 min1,676 subs |
| Bortle 6Bright suburban | 8 min128 subs | 34 min510 subs | 2 h 16 min2,038 subs |
| Bortle 7Suburban / urban transition | 11 min171 subs | 45 min683 subs | 3 h 02 min2,729 subs |
| Bortle 8City | 16 min238 subs | 1 h 03 min950 subs | 4 h 13 min3,800 subs |
| Bortle 9Inner city | 25 min381 subs | 1 h 41 min1,522 subs | 6 h 46 min6,086 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 44 min of run time. The Odyssey’s battery (rated about 5 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 power bank 20000mAh 5V 2.4AUnistellar says plain 5 V 2.4 A and warns against fast or adaptive chargers.
- 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 Odyssey →
How it frames
The Sagittarius Star Cloud is 90′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it is 2.7× wider than the frame. A mosaic, or choosing the part you want and letting the rest go, is how it gets shot on this scope.
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 Unistellar Odyssey
Unistellar’s compact 85 mm with autofocus and tiny pixels. Sharp, but the fine sampling costs time on faint extended targets. The Odyssey Pro is the same telescope with an eyepiece added, so these figures apply to both.
Fixed 4 s subs in Enhanced Vision; they cannot be changed. No filter option; Unistellar says third-party filters cannot be fitted to the Odyssey.
The Odyssey uses fixed 4 s subs, so the only levers you have are the sky you shoot from, the filter, and total time.
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 Odyssey? 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 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 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 Odyssey