How long to image the Tulip Nebula with the DwarfLab Draco
From a Bortle 6 suburban sky, the DwarfLab Draco needs about 1 h 52 min (225 subs of 30 s with the built-in dual-narrowband (Hα + OIII) filter) for a solid image of the Tulip Nebula. A quick look takes 28 min; a showpiece 7 h 30 min. Under a Bortle 3 rural sky the solid figure drops to 1 h 15 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 21% 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 | 18 min36 subs | 1 h 11 min143 subs | 4 h 45 min571 subs |
| Bortle 2Typical dark site | 18 min37 subs | 1 h 13 min146 subs | 4 h 50 min581 subs |
| Bortle 3Rural | 19 min38 subs | 1 h 15 min150 subs | 5 h600 subs |
| Bortle 4Rural / suburban transition | 20 min41 subs | 1 h 21 min162 subs | 5 h 23 min647 subs |
| Bortle 5Suburban | 22 min45 subs | 1 h 30 min180 subs | 6 h720 subs |
| Bortle 6Bright suburban | 28 min57 subs | 1 h 52 min225 subs | 7 h 30 min900 subs |
| Bortle 7Suburban / urban transition | 39 min78 subs | 2 h 35 min311 subs | 10 h1,243 subs |
| Bortle 8City | 55 min111 subs | 3 h 42 min444 subs | 15 h1,775 subs |
| Bortle 9Inner city | 1 h 31 min182 subs | 6 h 04 min728 subs | 24 h2,911 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 2 h 26 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.)
- 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.
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How it frames
The Tulip Nebula is 16′ × 9′ across. The Draco frames 1.66° × 1.24° at 1.46″ per pixel, so it fills 21% 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 15 min150 subs | 1 h 30 min180 subs | 2 h 35 min311 subs |
| 60 s | 54 min54 subs | 1 h 09 min69 subs | 2 h 14 min135 subs |
| 120 s | 1 h30 subs | 1 h30 subs | 2 h 04 min62 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 07 min135 subs | 1 h 56 min233 subs | 5 h 30 min660 subs |
| dual-narrowband (Hα + OIII) | 1 h 15 min150 subs | 1 h 30 min180 subs | 2 h 35 min311 subs |
About the Tulip Nebula
A compact hydrogen bloom in Cygnus near the black hole Cygnus X-1. Small and moderately faint; dual-band.
Sh2-101 · Emission nebula in Cygnus · magnitude 9.0 · 16′ × 9′ · best in Jul, Aug, Sep. 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 Tulip Nebula from a Draco? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Tulip Nebula with the ZWO Seestar S50: 2 h 22 min from Bortle 6
- Tulip Nebula with the ZWO Seestar S50 Pro: 2 h 40 min from Bortle 6
- Tulip Nebula with the ZWO Seestar S30: 2 h 47 min from Bortle 6
- Tulip Nebula with the ZWO Seestar S30 Pro: 2 h 53 min from Bortle 6
- Tulip Nebula with the DwarfLab DWARF 3: 2 h 55 min from Bortle 6
- Tulip Nebula with the DwarfLab DWARF mini: 2 h 20 min from Bortle 6
- Tulip Nebula with the DwarfLab DWARF II: 13 h from Bortle 6
- Tulip Nebula with the Vaonis Vespera II: 3 h 51 min from Bortle 6
- Tulip Nebula with the Vaonis Vespera Pro: 8 h 39 min from Bortle 6
- Tulip Nebula with the Vaonis Vespera 3: 3 h 41 min from Bortle 6
- Tulip Nebula with the Vaonis Vespera Pro 2: 8 h 15 min from Bortle 6
- Tulip Nebula with the Unistellar eQuinox 2: 3 h 32 min from Bortle 6
- Tulip Nebula with the Unistellar Odyssey: 16 h from Bortle 6
- Tulip Nebula with the Celestron Origin: 1 h 01 min from Bortle 6
- Tulip Nebula with the Celestron Origin Mark II: 1 h 24 min from Bortle 6
All telescopes for the Tulip Nebula · All targets for the Draco