How long to image the Heart Nebula with the DwarfLab Draco
From a Bortle 6 suburban sky, the DwarfLab Draco needs about 2 h 14 min (268 subs of 30 s with the built-in dual-narrowband (Hα + OIII) filter) for a solid image of the Heart Nebula. A quick look takes 33 min; a showpiece 8 h 54 min. Under a Bortle 3 rural sky the solid figure drops to 1 h 29 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 | 21 min43 subs | 1 h 24 min169 subs | 5 h 37 min674 subs |
| Bortle 2Typical dark site | 21 min43 subs | 1 h 26 min172 subs | 5 h 43 min686 subs |
| Bortle 3Rural | 22 min45 subs | 1 h 29 min178 subs | 5 h 54 min709 subs |
| Bortle 4Rural / suburban transition | 24 min48 subs | 1 h 36 min192 subs | 6 h 22 min765 subs |
| Bortle 5Suburban | 27 min54 subs | 1 h 47 min214 subs | 7 h 06 min853 subs |
| Bortle 6Bright suburban | 33 min67 subs | 2 h 14 min268 subs | 8 h 54 min1,069 subs |
| Bortle 7Suburban / urban transition | 46 min93 subs | 3 h 05 min371 subs | 12 h1,481 subs |
| Bortle 8City | 1 h 06 min133 subs | 4 h 25 min531 subs | 18 h2,121 subs |
| Bortle 9Inner city | 1 h 49 min218 subs | 7 h 16 min872 subs | 29 h3,486 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 2 h 54 min of run time. The Draco’s battery (rated about 5 h) 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 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.
Affiliate links: the retailer pays us a small commission and you pay the same price. These are search links to the named product, not endorsements of a particular listing; check the listing matches your model.
Everything that fits the Draco →
How it frames
The Heart Nebula is 60′ 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 29 min178 subs | 1 h 47 min214 subs | 3 h 05 min371 subs |
| 60 s | 1 h 03 min64 subs | 1 h 21 min82 subs | 2 h 40 min160 subs |
| 120 s | 1 h30 subs | 1 h 09 min35 subs | 2 h 27 min74 subs |
| 300 s | 2 h 30 min30 subs | 2 h 30 min30 subs | 2 h 30 min30 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| No filter | 1 h 20 min160 subs | 2 h 19 min278 subs | 6 h 35 min791 subs |
| dual-narrowband (Hα + OIII) | 1 h 29 min178 subs | 1 h 47 min214 subs | 3 h 05 min371 subs |
About the Heart Nebula
A degree-wide hydrogen cloud shaped like a heart, with the bright Melotte 15 cluster and pillars at its centre. Dual-band, and a wide field or mosaic.
IC 1805, Sh2-190 · Emission nebula in Cassiopeia · magnitude 6.5 · 60′ · 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 Heart Nebula from a Draco? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Heart Nebula with the ZWO Seestar S50: 2 h 49 min from Bortle 6
- Heart Nebula with the ZWO Seestar S50 Pro: 3 h 10 min from Bortle 6
- Heart Nebula with the ZWO Seestar S30: 3 h 19 min from Bortle 6
- Heart Nebula with the ZWO Seestar S30 Pro: 3 h 25 min from Bortle 6
- Heart Nebula with the DwarfLab DWARF 3: 3 h 27 min from Bortle 6
- Heart Nebula with the DwarfLab DWARF mini: 2 h 47 min from Bortle 6
- Heart Nebula with the DwarfLab DWARF II: 16 h from Bortle 6
- Heart Nebula with the Vaonis Vespera II: 4 h 37 min from Bortle 6
- Heart Nebula with the Vaonis Vespera Pro: 10 h from Bortle 6
- Heart Nebula with the Vaonis Vespera 3: 4 h 24 min from Bortle 6
- Heart Nebula with the Vaonis Vespera Pro 2: 9 h 52 min from Bortle 6
- Heart Nebula with the Unistellar eQuinox 2: 4 h 14 min from Bortle 6
- Heart Nebula with the Unistellar Odyssey: 20 h from Bortle 6
- Heart Nebula with the Celestron Origin: 1 h 13 min from Bortle 6
- Heart Nebula with the Celestron Origin Mark II: 1 h 40 min from Bortle 6
All telescopes for the Heart Nebula · All targets for the Draco