How long to image the Soul Nebula with the DwarfLab Draco
From a Bortle 6 suburban sky, the DwarfLab Draco needs about 2 h 39 min (318 subs of 30 s with the built-in dual-narrowband (Hα + OIII) filter) for a solid image of the Soul Nebula. A quick look takes 40 min; a showpiece 11 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 45 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 80% 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 | 25 min50 subs | 1 h 39 min199 subs | 6 h 38 min796 subs |
| Bortle 2Typical dark site | 25 min51 subs | 1 h 41 min203 subs | 6 h 45 min810 subs |
| Bortle 3Rural | 26 min53 subs | 1 h 45 min210 subs | 6 h 59 min838 subs |
| Bortle 4Rural / suburban transition | 28 min57 subs | 1 h 53 min227 subs | 7 h 32 min905 subs |
| Bortle 5Suburban | 32 min64 subs | 2 h 06 min253 subs | 8 h 25 min1,011 subs |
| Bortle 6Bright suburban | 40 min80 subs | 2 h 39 min318 subs | 11 h1,271 subs |
| Bortle 7Suburban / urban transition | 55 min111 subs | 3 h 41 min442 subs | 15 h1,767 subs |
| Bortle 8City | 1 h 19 min159 subs | 5 h 17 min634 subs | 21 h2,536 subs |
| Bortle 9Inner city | 2 h 11 min262 subs | 8 h 42 min1,045 subs | 35 h4,177 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 Draco’s battery is rated at about 5 h, less near freezing, which is cutting it fine; take a power bank. (Bortle 6, solid image; we allow 30% over the integration time, and 30% off the battery for a November night.)
- USB-C PD power bank 20000mAhRated 5 h on its 10,000 mAh battery. DwarfLab has not published the charging input, so check PD support before relying on it mid-session.
- 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 Draco →
How it frames
The Soul Nebula is 60′ × 30′ across. The Draco frames 1.66° × 1.24° at 1.46″ per pixel, so it fills 80% of the frame’s short side.
Longer subs
Auto Mode picks the exposure; Pro Mode allows up to 300 s, held by built-in guiding and field derotation. The 30 s default here is our assumption. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 30 s | 1 h 45 min210 subs | 2 h 06 min253 subs | 3 h 41 min442 subs |
| 60 s | 1 h 14 min75 subs | 1 h 36 min96 subs | 3 h 10 min191 subs |
| 120 s | 1 h30 subs | 1 h 21 min41 subs | 2 h 55 min88 subs |
| 300 s | 2 h 30 min30 subs | 2 h 30 min30 subs | 2 h 46 min34 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| No filter | 1 h 35 min190 subs | 2 h 45 min331 subs | 7 h 54 min949 subs |
| dual-narrowband (Hα + OIII) | 1 h 45 min210 subs | 2 h 06 min253 subs | 3 h 41 min442 subs |
About the Soul Nebula
The Heart's companion, a knobbly emission cloud full of pillars. Faint overall; long dual-band integrations reward you.
IC 1848, Sh2-199 · Emission nebula in Cassiopeia · magnitude 6.5 · 60′ × 30′ · best in Oct, Nov, Dec. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Emission nebulae glow in a few narrow lines, mostly hydrogen-alpha (deep red) and doubly ionised oxygen (teal). A dual-band filter passes those lines and blocks most skyglow, which is why it cuts the time needed from a suburban sky so dramatically. Use it. From a genuinely dark site the gain is smaller because there is less skyglow to block, and read noise becomes the limit, which is where longer subs (EQ mode, or Expert Mode on a Vespera) earn their keep.
Stars lose colour through a dual-band filter; a short broadband stack blended in fixes that if you care.
About the DwarfLab Draco
DwarfLab’s big scope: 90 mm of folded f/3.8 optics, the most aperture of any Seestar or DWARF, a narrow 13 nm dual-band filter and 300 s subs with built-in guiding. A small-target scope; big nebulae need its mosaic mode.
Auto Mode picks the exposure; Pro Mode allows up to 300 s, held by built-in guiding and field derotation. The 30 s default here is our assumption. Built-in Hα + OIII dual-narrowband filter, 13 nm per line; the SHO Edition adds an SII option.
Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 30 s and 300 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 Soul Nebula from a Draco? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Soul Nebula with the ZWO Seestar S50: 3 h 21 min from Bortle 6
- Soul Nebula with the ZWO Seestar S50 Pro: 3 h 46 min from Bortle 6
- Soul Nebula with the ZWO Seestar S30: 3 h 57 min from Bortle 6
- Soul Nebula with the ZWO Seestar S30 Pro: 4 h 04 min from Bortle 6
- Soul Nebula with the DwarfLab DWARF 3: 4 h 06 min from Bortle 6
- Soul Nebula with the DwarfLab DWARF mini: 3 h 18 min from Bortle 6
- Soul Nebula with the DwarfLab DWARF II: 19 h from Bortle 6
- Soul Nebula with the Vaonis Vespera II: 5 h 31 min from Bortle 6
- Soul Nebula with the Vaonis Vespera Pro: 12 h from Bortle 6
- Soul Nebula with the Vaonis Vespera 3: 5 h 16 min from Bortle 6
- Soul Nebula with the Vaonis Vespera Pro 2: 12 h from Bortle 6
- Soul Nebula with the Unistellar eQuinox 2: 5 h 05 min from Bortle 6
- Soul Nebula with the Unistellar Odyssey: 24 h from Bortle 6
- Soul Nebula with the Celestron Origin: 1 h 27 min from Bortle 6
- Soul Nebula with the Celestron Origin Mark II: 2 h from Bortle 6
All telescopes for the Soul Nebula · All targets for the Draco