How long to image the Southern Pinwheel with the DwarfLab DWARF II
From a Bortle 6 suburban sky, the DwarfLab DWARF II needs about 2 h 39 min (635 subs of 15 s) for a solid image of the Southern Pinwheel. A quick look takes 40 min; a showpiece 11 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 23 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 12% 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 | 19 min76 subs | 1 h 15 min301 subs | 5 h1,202 subs |
| Bortle 2Typical dark site | 19 min78 subs | 1 h 18 min311 subs | 5 h 11 min1,243 subs |
| Bortle 3Rural | 21 min83 subs | 1 h 23 min331 subs | 5 h 30 min1,321 subs |
| Bortle 4Rural / suburban transition | 24 min95 subs | 1 h 34 min378 subs | 6 h 17 min1,509 subs |
| Bortle 5Suburban | 28 min113 subs | 1 h 53 min452 subs | 7 h 32 min1,807 subs |
| Bortle 6Bright suburban | 40 min159 subs | 2 h 39 min635 subs | 11 h2,539 subs |
| Bortle 7Suburban / urban transition | 1 h 01 min246 subs | 4 h 06 min984 subs | 16 h3,933 subs |
| Bortle 8City | 1 h 35 min382 subs | 6 h 21 min1,525 subs | 25 h6,097 subs |
| Bortle 9Inner city | 2 h 47 min670 subs | 11 h2,679 subs | 45 h10,713 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 3 h 26 min of run time. The DWARF II’s battery is rated at about 3 h, so the session needs an external power bank. (Bortle 6, solid image; we allow 30% over the integration time.)
- USB-C PD power bank 10000mAh 18W18 W PD input; runs while charging.
- 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 DWARF II →
How it frames
The Southern Pinwheel is 13′ × 12′ across. The DWARF II frames 3.19° × 1.79° at 2.99″ per pixel, so it fills 12% 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 DwarfLab DWARF II
The original pocket scope. 24 mm aperture and tiny 1.45 µm pixels mean it is slow per pixel, so bin or downsample and be patient.
15 s is the hard maximum in any mode; DwarfLab recommends EQ mode at 15 s. Two built-in filters, VIS and Astro (IR-pass); no dual-band. The optional UHC filter is no longer sold.
The DWARF II uses fixed 15 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 DWARF II? 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 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 Unistellar Odyssey: 3 h 12 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 DWARF II