How long to image the Iris Nebula with the DwarfLab DWARF II
From a Bortle 6 suburban sky, the DwarfLab DWARF II needs about 6 h 29 min (1,556 subs of 15 s) for a solid image of the Iris Nebula. A quick look takes 1 h 37 min; a showpiece 26 h. Under a Bortle 3 rural sky the solid figure drops to 3 h 14 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 17% 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 | 44 min175 subs | 2 h 55 min700 subs | 12 h2,797 subs |
| Bortle 2Typical dark site | 45 min182 subs | 3 h 01 min726 subs | 12 h2,902 subs |
| Bortle 3Rural | 48 min194 subs | 3 h 14 min776 subs | 13 h3,102 subs |
| Bortle 4Rural / suburban transition | 56 min224 subs | 3 h 44 min896 subs | 15 h3,584 subs |
| Bortle 5Suburban | 1 h 08 min272 subs | 4 h 32 min1,087 subs | 18 h4,348 subs |
| Bortle 6Bright suburban | 1 h 37 min389 subs | 6 h 29 min1,556 subs | 26 h6,223 subs |
| Bortle 7Suburban / urban transition | 2 h 33 min613 subs | 10 h2,450 subs | 41 h9,797 subs |
| Bortle 8City | 4 h960 subs | 16 h3,837 subs | 64 h15,345 subs |
| Bortle 9Inner city | 7 h 05 min1,699 subs | 28 h6,795 subs | 110+ h27,177 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 8 h 26 min of run time. That is more than one night: over 2 nights, about 4 h 13 min each. The DWARF II’s battery is rated at about 3 h, so each night needs an external power bank. (Bortle 6, solid image; we allow 30% over the integration time.)
- USB-C PD power bank 10000mAh 18W18 W PD input; runs while charging.
- 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 II →
How it frames
The Iris Nebula is 18′ across. The DWARF II frames 3.19° × 1.79° at 2.99″ per pixel, so it fills 17% of the frame’s short side.
About the Iris Nebula
A blue reflection nebula wrapped in dark dust. No filter helps, and the surrounding dust needs a dark sky and hours.
NGC 7023, Caldwell 4 · Reflection nebula in Cepheus · magnitude 6.8 · 18′ · best in Jul, Aug, Sep. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Reflection nebulae are starlight scattered by dust, so they are broadband and blue. A dual-band filter removes almost all of it; do not use one. These are among the faintest structures a smart scope can attempt and the figures run long. A dark sky matters more here than for any other type, and the Moon must be down.
About the DwarfLab DWARF II
The original pocket scope. 24 mm aperture and tiny 1.45 µm pixels mean it is slow per pixel, so bin or downsample and be patient.
15 s is the hard maximum in any mode; DwarfLab recommends EQ mode at 15 s. Two built-in filters, VIS and Astro (IR-pass); no dual-band. The optional UHC filter is no longer sold.
The DWARF II uses fixed 15 s subs, so the only levers you have are the sky you shoot from, the filter, and total time.
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 Iris Nebula from a DWARF II? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Iris Nebula with the ZWO Seestar S50: 1 h 53 min from Bortle 6
- Iris Nebula with the ZWO Seestar S50 Pro: 2 h 04 min from Bortle 6
- Iris Nebula with the ZWO Seestar S30: 1 h 59 min from Bortle 6
- Iris Nebula with the ZWO Seestar S30 Pro: 2 h 12 min from Bortle 6
- Iris Nebula with the DwarfLab DWARF 3: 2 h 45 min from Bortle 6
- Iris Nebula with the DwarfLab DWARF mini: 1 h 53 min from Bortle 6
- Iris Nebula with the DwarfLab Draco: 1 h 33 min from Bortle 6
- Iris Nebula with the Vaonis Vespera II: 1 h 53 min from Bortle 6
- Iris Nebula with the Vaonis Vespera Pro: 4 h 14 min from Bortle 6
- Iris Nebula with the Vaonis Vespera 3: 1 h 48 min from Bortle 6
- Iris Nebula with the Vaonis Vespera Pro 2: 4 h 02 min from Bortle 6
- Iris Nebula with the Unistellar eQuinox 2: 1 h 43 min from Bortle 6
- Iris Nebula with the Unistellar Odyssey: 7 h 58 min from Bortle 6
- Iris Nebula with the Celestron Origin: 30 min from Bortle 6
- Iris Nebula with the Celestron Origin Mark II: 41 min from Bortle 6
All telescopes for the Iris Nebula · All targets for the DWARF II