How long to image the Jellyfish Nebula with the DwarfLab DWARF 3
From a Bortle 6 suburban sky, the DwarfLab DWARF 3 needs about 4 h 52 min (1,169 subs of 15 s with the built-in dual-band filter) for a solid image of the Jellyfish Nebula. A quick look takes 1 h 13 min; a showpiece 19 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 51 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 51% 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 | 40 min160 subs | 2 h 40 min639 subs | 11 h2,555 subs |
| Bortle 2Typical dark site | 41 min164 subs | 2 h 44 min655 subs | 11 h2,620 subs |
| Bortle 3Rural | 43 min172 subs | 2 h 51 min686 subs | 11 h2,743 subs |
| Bortle 4Rural / suburban transition | 48 min191 subs | 3 h 10 min761 subs | 13 h3,041 subs |
| Bortle 5Suburban | 55 min220 subs | 3 h 40 min879 subs | 15 h3,514 subs |
| Bortle 6Bright suburban | 1 h 13 min293 subs | 4 h 52 min1,169 subs | 19 h4,673 subs |
| Bortle 7Suburban / urban transition | 1 h 48 min431 subs | 7 h 10 min1,721 subs | 29 h6,881 subs |
| Bortle 8City | 2 h 41 min645 subs | 11 h2,578 subs | 43 h10,310 subs |
| Bortle 9Inner city | 4 h 35 min1,102 subs | 18 h4,406 subs | 73 h17,624 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 6 h 20 min of run time. The DWARF 3’s battery is rated at about 5 h 30 min, 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 January night.)
- USB-C PD power bank 20000mAh 18W18 W PD input and it runs while charging; needs a C-to-C cable for PD.
- 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 3 →
How it frames
The Jellyfish Nebula is 50′ × 40′ across. The DWARF 3 frames 2.93° × 1.65° at 2.75″ per pixel, so it fills 51% of the frame’s short side.
Longer subs
Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 60 s is the ceiling on the tele camera. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 15 s | 2 h 51 min686 subs | 3 h 40 min879 subs | 7 h 10 min1,721 subs |
| 30 s | 2 h 24 min288 subs | 3 h 12 min384 subs | 6 h 42 min805 subs |
| 60 s | 2 h 10 min130 subs | 2 h 58 min178 subs | 6 h 28 min389 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| Astro (no light-pollution filter) | 3 h722 subs | 5 h 38 min1,351 subs | 17 h4,101 subs |
| dual-band | 2 h 51 min686 subs | 3 h 40 min879 subs | 7 h 10 min1,721 subs |
About the Jellyfish Nebula
A supernova remnant beside Propus in Gemini, with a bright rim like a jellyfish bell. Faint; dual-band and hours.
IC 443, Sh2-248 · Supernova remnant in Gemini · magnitude 12.0 · 50′ × 40′ · best in Dec, Jan, Feb. 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 3
Small pixels on a 35 mm f/4.3 lens give a sharper image than its aperture suggests, and EQ mode with 60 s subs makes it the read-noise winner in dark skies.
Auto mode caps subs at 15 s; 30 s and longer need EQ mode, and 60 s is the ceiling on the tele camera. Three built-in filters: VIS, Astro (430 to 690 nm) and dual-band Hα 656 nm / OIII 501 nm.
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 60 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 Jellyfish Nebula from a DWARF 3? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Jellyfish Nebula with the ZWO Seestar S50: 4 h from Bortle 6
- Jellyfish Nebula with the ZWO Seestar S50 Pro: 4 h 30 min from Bortle 6
- Jellyfish Nebula with the ZWO Seestar S30: 4 h 43 min from Bortle 6
- Jellyfish Nebula with the ZWO Seestar S30 Pro: 4 h 51 min from Bortle 6
- Jellyfish Nebula with the DwarfLab DWARF mini: 3 h 56 min from Bortle 6
- Jellyfish Nebula with the DwarfLab Draco: 3 h 09 min from Bortle 6
- Jellyfish Nebula with the DwarfLab DWARF II: 23 h from Bortle 6
- Jellyfish Nebula with the Vaonis Vespera II: 6 h 37 min from Bortle 6
- Jellyfish Nebula with the Vaonis Vespera Pro: 15 h from Bortle 6
- Jellyfish Nebula with the Vaonis Vespera 3: 6 h 19 min from Bortle 6
- Jellyfish Nebula with the Vaonis Vespera Pro 2: 14 h from Bortle 6
- Jellyfish Nebula with the Unistellar eQuinox 2: 6 h 05 min from Bortle 6
- Jellyfish Nebula with the Unistellar Odyssey: 28 h from Bortle 6
- Jellyfish Nebula with the Celestron Origin: 1 h 45 min from Bortle 6
- Jellyfish Nebula with the Celestron Origin Mark II: 2 h 23 min from Bortle 6
All telescopes for the Jellyfish Nebula · All targets for the DWARF 3