How long to image the Crab Nebula with the DwarfLab DWARF II
From a Bortle 6 suburban sky, the DwarfLab DWARF II needs about 2 h 08 min (513 subs of 15 s) for a solid image of the Crab Nebula. A quick look takes 32 min; a showpiece 8 h 33 min. Under a Bortle 3 rural sky the solid figure drops to 1 h 10 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 6% 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 | 16 min65 subs | 1 h 05 min259 subs | 4 h 19 min1,035 subs |
| Bortle 2Typical dark site | 17 min67 subs | 1 h 07 min267 subs | 4 h 27 min1,067 subs |
| Bortle 3Rural | 18 min71 subs | 1 h 10 min282 subs | 4 h 41 min1,126 subs |
| Bortle 4Rural / suburban transition | 20 min80 subs | 1 h 19 min318 subs | 5 h 17 min1,269 subs |
| Bortle 5Suburban | 23 min94 subs | 1 h 33 min374 subs | 6 h 14 min1,495 subs |
| Bortle 6Bright suburban | 32 min129 subs | 2 h 08 min513 subs | 8 h 33 min2,052 subs |
| Bortle 7Suburban / urban transition | 49 min195 subs | 3 h 14 min778 subs | 13 h3,111 subs |
| Bortle 8City | 1 h 14 min298 subs | 4 h 57 min1,190 subs | 20 h4,757 subs |
| Bortle 9Inner city | 2 h 09 min517 subs | 8 h 37 min2,067 subs | 34 h8,267 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 2 h 47 min of run time. The DWARF II’s battery is rated at about 3 h, less near freezing, so the session needs an external power bank. (Bortle 6, solid image; we allow 30% over the integration time, and 30% off the battery for a December night.)
- 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.
- hand warmers long lastingAir-activated packs give hours of heat for the person; winter nights are long and you spend most of them standing still.
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Everything that fits the DWARF II →
How it frames
The Crab Nebula is 6′ × 4′ across. The DWARF II frames 3.19° × 1.79° at 2.99″ per pixel, so it fills 6% of the frame’s short side.
Filters
The Crab Nebula is an emission target, where a dual-band filter would normally cut the time several-fold from a lit sky, but the DWARF II has no dual-band option: Two built-in filters, VIS and Astro (IR-pass); no dual-band. The optional UHC filter is no longer sold. The figures above are for the Astro position, and a darker sky is the lever that remains.
About the Crab Nebula
The remains of the supernova of 1054, a tangle of filaments around a pulsar. Small but bright enough for a good result in an evening.
M1, NGC 1952 · Supernova remnant in Taurus · magnitude 8.4 · 6′ × 4′ · best in Nov, Dec, Jan. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Supernova remnants are emission-line objects, strong in both hydrogen-alpha and OIII, and their filaments are thin, so pixel scale matters as much as aperture. A dual-band filter is essential from any lit sky and still helps under a dark one. These are long-integration targets; plan on several sessions and stack across nights.
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 Crab Nebula from a DWARF II? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Crab Nebula with the ZWO Seestar S50: 28 min from Bortle 6
- Crab Nebula with the ZWO Seestar S50 Pro: 31 min from Bortle 6
- Crab Nebula with the ZWO Seestar S30: 31 min from Bortle 6
- Crab Nebula with the ZWO Seestar S30 Pro: 33 min from Bortle 6
- Crab Nebula with the DwarfLab DWARF 3: 37 min from Bortle 6
- Crab Nebula with the DwarfLab DWARF mini: 28 min from Bortle 6
- Crab Nebula with the DwarfLab Draco: 22 min from Bortle 6
- Crab Nebula with the Vaonis Vespera II: 38 min from Bortle 6
- Crab Nebula with the Vaonis Vespera Pro: 1 h 25 min from Bortle 6
- Crab Nebula with the Vaonis Vespera 3: 37 min from Bortle 6
- Crab Nebula with the Vaonis Vespera Pro 2: 1 h 21 min from Bortle 6
- Crab Nebula with the Unistellar eQuinox 2: 34 min from Bortle 6
- Crab Nebula with the Unistellar Odyssey: 2 h 32 min from Bortle 6
- Crab Nebula with the Celestron Origin: 10 min from Bortle 6
- Crab Nebula with the Celestron Origin Mark II: 14 min from Bortle 6
All telescopes for the Crab Nebula · All targets for the DWARF II