How long to image the Helix Nebula with the DwarfLab DWARF mini
From a Bortle 6 suburban sky, the DwarfLab DWARF mini needs about 1 h 58 min (473 subs of 15 s with the built-in dual-band filter) for a solid image of the Helix Nebula. A quick look takes 30 min; a showpiece 7 h 52 min. Under a Bortle 3 rural sky the solid figure drops to 1 h 21 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 35% 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 min78 subs | 1 h 17 min309 subs | 5 h 08 min1,233 subs |
| Bortle 2Typical dark site | 20 min79 subs | 1 h 18 min314 subs | 5 h 13 min1,253 subs |
| Bortle 3Rural | 20 min81 subs | 1 h 21 min323 subs | 5 h 23 min1,291 subs |
| Bortle 4Rural / suburban transition | 22 min87 subs | 1 h 26 min346 subs | 5 h 46 min1,383 subs |
| Bortle 5Suburban | 24 min96 subs | 1 h 36 min383 subs | 6 h 22 min1,530 subs |
| Bortle 6Bright suburban | 30 min119 subs | 1 h 58 min473 subs | 7 h 52 min1,889 subs |
| Bortle 7Suburban / urban transition | 40 min161 subs | 2 h 41 min644 subs | 11 h2,573 subs |
| Bortle 8City | 57 min228 subs | 3 h 47 min909 subs | 15 h3,636 subs |
| Bortle 9Inner city | 1 h 32 min369 subs | 6 h 09 min1,476 subs | 25 h5,902 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 2 h 33 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.)
- 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.
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Everything that fits the DWARF mini →
How it frames
The Helix Nebula is 25′ × 22′ across. The DWARF mini frames 2.13° × 1.20° at 3.99″ per pixel, so it fills 35% 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 | 1 h 21 min323 subs | 1 h 36 min383 subs | 2 h 41 min644 subs |
| 30 s | 58 min117 subs | 1 h 13 min147 subs | 2 h 18 min277 subs |
| 60 s | 47 min48 subs | 1 h 02 min63 subs | 2 h 07 min128 subs |
| 90 s | 45 min30 subs | 58 min39 subs | 2 h 04 min83 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| Astro (no light-pollution filter) | 1 h 10 min282 subs | 1 h 59 min477 subs | 5 h 32 min1,329 subs |
| dual-band | 1 h 21 min323 subs | 1 h 36 min383 subs | 2 h 41 min644 subs |
About the Helix Nebula
The nearest bright planetary nebula, half the Moon's width but spread thin. Low from the UK; dual-band and a couple of hours make the eye appear.
NGC 7293, Caldwell 63 · Planetary nebula in Aquarius · magnitude 7.3 · 25′ × 22′ · best in Aug, Sep, Oct. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Planetary nebulae are small but intensely bright per pixel in OIII and H-alpha, so they respond very well to a dual-band filter and do not need much time for the main shell. The faint outer halos most of them have are a different proposition and need hours. Keep subs short if the central region saturates.
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 Helix 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
- Helix Nebula with the ZWO Seestar S50: 2 h from Bortle 6
- Helix Nebula with the ZWO Seestar S50 Pro: 2 h 15 min from Bortle 6
- Helix Nebula with the ZWO Seestar S30: 2 h 20 min from Bortle 6
- Helix Nebula with the ZWO Seestar S30 Pro: 2 h 25 min from Bortle 6
- Helix Nebula with the DwarfLab DWARF 3: 2 h 28 min from Bortle 6
- Helix Nebula with the DwarfLab Draco: 1 h 35 min from Bortle 6
- Helix Nebula with the DwarfLab DWARF II: 11 h from Bortle 6
- Helix Nebula with the Vaonis Vespera II: 3 h 13 min from Bortle 6
- Helix Nebula with the Vaonis Vespera Pro: 7 h 14 min from Bortle 6
- Helix Nebula with the Vaonis Vespera 3: 3 h 05 min from Bortle 6
- Helix Nebula with the Vaonis Vespera Pro 2: 6 h 53 min from Bortle 6
- Helix Nebula with the Unistellar eQuinox 2: 2 h 57 min from Bortle 6
- Helix Nebula with the Unistellar Odyssey: 14 h from Bortle 6
- Helix Nebula with the Celestron Origin: 51 min from Bortle 6
- Helix Nebula with the Celestron Origin Mark II: 1 h 10 min from Bortle 6
All telescopes for the Helix Nebula · All targets for the DWARF mini