How long to image the Helix Nebula with the DwarfLab DWARF II

From a Bortle 6 suburban sky, the DwarfLab DWARF II needs about 11 h (2,663 subs of 15 s) for a solid image of the Helix Nebula. A quick look takes 2 h 46 min; a showpiece 44 h. Under a Bortle 3 rural sky the solid figure drops to 5 h 26 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 23% of the frame’s short side.

Helix Nebula with the DwarfLab DWARF II: 15 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site1 h 13 min294 subs4 h 53 min1,174 subs20 h4,695 subs
Bortle 2Typical dark site1 h 16 min305 subs5 h 05 min1,220 subs20 h4,878 subs
Bortle 3Rural1 h 22 min327 subs5 h 26 min1,306 subs22 h5,224 subs
Bortle 4Rural / suburban transition1 h 35 min379 subs6 h 19 min1,516 subs25 h6,062 subs
Bortle 5Suburban1 h 55 min462 subs7 h 42 min1,848 subs31 h7,390 subs
Bortle 6Bright suburban2 h 46 min666 subs11 h2,663 subs44 h10,649 subs
Bortle 7Suburban / urban transition4 h 23 min1,054 subs18 h4,215 subs70 h16,859 subs
Bortle 8City6 h 54 min1,657 subs28 h6,625 subs110+ h26,500 subs
Bortle 9Inner city12 h2,942 subs49 h11,766 subs200+ h47,063 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 14 h of run time. That is more than one night: over 3 nights, about 4 h 48 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.)

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 DWARF II →

How it frames

The Helix Nebula is 25′ × 22′ across. The DWARF II frames 3.19° × 1.79° at 2.99″ per pixel, so it fills 23% of the frame’s short side.

Filters

The Helix 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 Helix Nebula

The nearest bright planetary nebula, half the Moon's width but spread thin. Low from the UK; dual-band and a couple of hours make the eye appear.

NGC 7293, Caldwell 63 · Planetary nebula in Aquarius · magnitude 7.3 · 25′ × 22′ · best in Aug, Sep, Oct. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Planetary nebulae are small but intensely bright per pixel in OIII and H-alpha, so they respond very well to a dual-band filter and do not need much time for the main shell. The faint outer halos most of them have are a different proposition and need hours. Keep subs short if the central region saturates.

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.

Where to buy the DWARF IIAmazon UKAmazon USAffiliate links: As an Amazon Associate I earn from qualifying purchases, at no cost to you.
Imaged the Helix Nebula with your DWARF II? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Helix 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

All telescopes for the Helix Nebula · All targets for the DWARF II