How long to image the Crab Nebula with the DwarfLab DWARF mini
From a Bortle 6 suburban sky, the DwarfLab DWARF mini needs about 28 min (111 subs of 15 s with the built-in dual-band filter) for a solid image of the Crab Nebula. A quick look takes 7 min; a showpiece 1 h 51 min. Under a Bortle 3 rural sky the solid figure drops to 21 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 8% 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 | 5 min21 subs | 21 min83 subs | 1 h 23 min331 subs |
| Bortle 2Typical dark site | 5 min21 subs | 21 min84 subs | 1 h 23 min334 subs |
| Bortle 3Rural | 5 min22 subs | 21 min86 subs | 1 h 25 min341 subs |
| Bortle 4Rural / suburban transition | 6 min23 subs | 22 min90 subs | 1 h 29 min357 subs |
| Bortle 5Suburban | 6 min24 subs | 24 min96 subs | 1 h 35 min382 subs |
| Bortle 6Bright suburban | 7 min28 subs | 28 min111 subs | 1 h 51 min443 subs |
| Bortle 7Suburban / urban transition | 9 min35 subs | 35 min140 subs | 2 h 20 min560 subs |
| Bortle 8City | 12 min47 subs | 46 min186 subs | 3 h 05 min741 subs |
| Bortle 9Inner city | 18 min71 subs | 1 h 10 min282 subs | 4 h 42 min1,128 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 36 min of run time. The DWARF mini’s battery (rated about 3 h 30 min) 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, and 30% off the battery for a December night.)
- USB-C PD power bank 10000mAh 20W7,000 mAh inside, about four hours; a PD bank extends the night.
- 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 mini →
How it frames
The Crab Nebula is 6′ × 4′ across. The DWARF mini frames 2.13° × 1.20° at 3.99″ per pixel, so it fills 8% of the frame’s short side.
Longer subs
Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 90 s is the ceiling. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 15 s | 21 min86 subs | 24 min96 subs | 35 min140 subs |
| 30 s | 17 min35 subs | 20 min41 subs | 31 min63 subs |
| 60 s | 30 min30 subs | 30 min30 subs | 30 min30 subs |
| 90 s | 45 min30 subs | 45 min30 subs | 45 min30 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| Astro (no light-pollution filter) | 17 min70 subs | 26 min103 subs | 1 h 02 min248 subs |
| dual-band | 21 min86 subs | 24 min96 subs | 35 min140 subs |
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 mini
DwarfLab’s answer to the Seestar S30: same sensor and focal length, big pixels, dual-band filter built in, and 90 s subs in EQ mode. Sensitivity over megapixels.
Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 90 s is the ceiling. Built-in Astro (430 to 690 nm), dark-frame and dual-band Hα / OIII filters; no plain VIS filter on the tele camera.
Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 15 s and 90 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 Crab Nebula from a DWARF mini? 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 Draco: 22 min from Bortle 6
- Crab Nebula with the DwarfLab DWARF II: 2 h 08 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 mini