How long to image the Southern Pinwheel with the Unistellar Odyssey
From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 3 h 12 min (2,884 subs of 4 s) for a solid image of the Southern Pinwheel. A quick look takes 48 min; a showpiece 13 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 10 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 39% 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 | 31 min466 subs | 2 h 04 min1,861 subs | 8 h 16 min7,443 subs |
| Bortle 2Typical dark site | 32 min473 subs | 2 h 06 min1,892 subs | 8 h 25 min7,568 subs |
| Bortle 3Rural | 33 min488 subs | 2 h 10 min1,952 subs | 8 h 40 min7,806 subs |
| Bortle 4Rural / suburban transition | 35 min524 subs | 2 h 20 min2,096 subs | 9 h 19 min8,382 subs |
| Bortle 5Suburban | 39 min581 subs | 2 h 35 min2,324 subs | 10 h9,295 subs |
| Bortle 6Bright suburban | 48 min721 subs | 3 h 12 min2,884 subs | 13 h11,534 subs |
| Bortle 7Suburban / urban transition | 1 h 06 min988 subs | 4 h 23 min3,951 subs | 18 h15,802 subs |
| Bortle 8City | 1 h 33 min1,402 subs | 6 h 14 min5,607 subs | 25 h22,428 subs |
| Bortle 9Inner city | 2 h 32 min2,285 subs | 10 h9,140 subs | 41 h36,559 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 4 h 10 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.
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Everything that fits the Odyssey →
How it frames
The Southern Pinwheel is 13′ × 12′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it fills 39% of the frame’s short side.
About the Southern Pinwheel
A bright barred spiral, superb from the southern hemisphere and a low-altitude struggle from northern Europe.
M83, NGC 5236 · Galaxy in Hydra · magnitude 7.6 · 13′ × 12′ · best in Mar, Apr, May. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.
Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.
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 Southern Pinwheel from a Odyssey? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Southern Pinwheel with the ZWO Seestar S50: 47 min from Bortle 6
- Southern Pinwheel with the ZWO Seestar S50 Pro: 51 min from Bortle 6
- Southern Pinwheel with the ZWO Seestar S30: 49 min from Bortle 6
- Southern Pinwheel with the ZWO Seestar S30 Pro: 54 min from Bortle 6
- Southern Pinwheel with the DwarfLab DWARF 3: 1 h 08 min from Bortle 6
- Southern Pinwheel with the DwarfLab DWARF mini: 47 min from Bortle 6
- Southern Pinwheel with the DwarfLab Draco: 38 min from Bortle 6
- Southern Pinwheel with the DwarfLab DWARF II: 2 h 39 min from Bortle 6
- Southern Pinwheel with the Vaonis Vespera II: 47 min from Bortle 6
- Southern Pinwheel with the Vaonis Vespera Pro: 1 h 44 min from Bortle 6
- Southern Pinwheel with the Vaonis Vespera 3: 45 min from Bortle 6
- Southern Pinwheel with the Vaonis Vespera Pro 2: 1 h 40 min from Bortle 6
- Southern Pinwheel with the Unistellar eQuinox 2: 42 min from Bortle 6
- Southern Pinwheel with the Celestron Origin: 12 min from Bortle 6
- Southern Pinwheel with the Celestron Origin Mark II: 17 min from Bortle 6
All telescopes for the Southern Pinwheel · All targets for the Odyssey