How long to image the Cocoon Nebula with the DwarfLab DWARF II
From a Bortle 6 suburban sky, the DwarfLab DWARF II needs about 17 h (3,984 subs of 15 s) for a solid image of the Cocoon Nebula. A quick look takes 4 h 09 min; a showpiece 66 h. Under a Bortle 3 rural sky the solid figure drops to 8 h 06 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 11% 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 | 1 h 49 min437 subs | 7 h 17 min1,747 subs | 29 h6,987 subs |
| Bortle 2Typical dark site | 1 h 53 min454 subs | 7 h 34 min1,816 subs | 30 h7,262 subs |
| Bortle 3Rural | 2 h 02 min487 subs | 8 h 06 min1,946 subs | 32 h7,782 subs |
| Bortle 4Rural / suburban transition | 2 h 21 min566 subs | 9 h 25 min2,261 subs | 38 h9,041 subs |
| Bortle 5Suburban | 2 h 52 min690 subs | 11 h2,760 subs | 46 h11,037 subs |
| Bortle 6Bright suburban | 4 h 09 min996 subs | 17 h3,984 subs | 66 h15,935 subs |
| Bortle 7Suburban / urban transition | 6 h 35 min1,580 subs | 26 h6,317 subs | 110+ h25,267 subs |
| Bortle 8City | 10 h2,485 subs | 41 h9,939 subs | 170+ h39,756 subs |
| Bortle 9Inner city | 18 h4,417 subs | 74 h17,665 subs | 290+ h70,658 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 22 h of run time. That is more than one night: over 4 nights, about 5 h 24 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 Cocoon Nebula is 12′ across. The DWARF II frames 3.19° × 1.79° at 2.99″ per pixel, so it fills 11% of the frame’s short side.
Filters
The Cocoon Nebula is an emission target, where a dual-band filter would normally cut the time several-fold from a lit sky, but the DWARF II has no dual-band option: Two built-in filters, VIS and Astro (IR-pass); no dual-band. The optional UHC filter is no longer sold. The figures above are for the Astro position, and a darker sky is the lever that remains.
About the Cocoon Nebula
A round emission and reflection nebula at the end of a long dark lane. Mixed light, so a broadband stack keeps the blue.
IC 5146, Caldwell 19 · Emission nebula in Cygnus · magnitude 7.2 · 12′ · 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 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 Cocoon 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
- Cocoon Nebula with the ZWO Seestar S50: 2 h 58 min from Bortle 6
- Cocoon Nebula with the ZWO Seestar S50 Pro: 3 h 20 min from Bortle 6
- Cocoon Nebula with the ZWO Seestar S30: 3 h 29 min from Bortle 6
- Cocoon Nebula with the ZWO Seestar S30 Pro: 3 h 36 min from Bortle 6
- Cocoon Nebula with the DwarfLab DWARF 3: 3 h 39 min from Bortle 6
- Cocoon Nebula with the DwarfLab DWARF mini: 2 h 55 min from Bortle 6
- Cocoon Nebula with the DwarfLab Draco: 2 h 21 min from Bortle 6
- Cocoon Nebula with the Vaonis Vespera II: 4 h 49 min from Bortle 6
- Cocoon Nebula with the Vaonis Vespera Pro: 11 h from Bortle 6
- Cocoon Nebula with the Vaonis Vespera 3: 4 h 36 min from Bortle 6
- Cocoon Nebula with the Vaonis Vespera Pro 2: 10 h from Bortle 6
- Cocoon Nebula with the Unistellar eQuinox 2: 4 h 25 min from Bortle 6
- Cocoon Nebula with the Unistellar Odyssey: 21 h from Bortle 6
- Cocoon Nebula with the Celestron Origin: 1 h 16 min from Bortle 6
- Cocoon Nebula with the Celestron Origin Mark II: 1 h 44 min from Bortle 6
All telescopes for the Cocoon Nebula · All targets for the DWARF II