How long should I image the Cocoon Nebula with the Origin from a Bortle 6 sky?

About 1 h 16 min of total integration for a solid image, or 5 h 05 min for a showpiece. A quick look takes 19 min.

How many subs is that on the Origin?

At the default 10 s sub length, 458 subs for a solid image from Bortle 6 and 146 from Bortle 3.

Does a dual-band filter help on the Cocoon Nebula?

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 1 h 16 min to 39 min.

How long to image the Cocoon Nebula with the Celestron Origin

From a Bortle 6 suburban sky, the Celestron Origin needs about 1 h 16 min (458 subs of 10 s) for a solid image of the Cocoon Nebula. A quick look takes 19 min; a showpiece 5 h 05 min. Under a Bortle 3 rural sky the solid figure drops to 24 min. At Bortle 6 the limit is skyglow, so a darker site or a filter helps more than longer subs. In this scope's field it fills 23% of the frame’s short side.

Cocoon Nebula with the Celestron Origin: 10 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	5 min29 subs	19 min116 subs	1 h 17 min461 subs
Bortle 2Typical dark site	5 min32 subs	21 min126 subs	1 h 24 min503 subs
Bortle 3Rural	6 min37 subs	24 min146 subs	1 h 37 min583 subs
Bortle 4Rural / suburban transition	8 min49 subs	32 min194 subs	2 h 09 min776 subs
Bortle 5Suburban	11 min68 subs	45 min271 subs	3 h1,081 subs
Bortle 6Bright suburban	19 min115 subs	1 h 16 min458 subs	5 h 05 min1,832 subs
Bortle 7Suburban / urban transition	34 min204 subs	2 h 16 min816 subs	9 h 03 min3,261 subs
Bortle 8City	57 min343 subs	3 h 48 min1,371 subs	15 h5,481 subs
Bortle 9Inner city	1 h 46 min639 subs	7 h 06 min2,554 subs	28 h10,215 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 39 min of run time. The Origin’s battery (rated about 6 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.)

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How it frames

The Cocoon Nebula is 12′ across. The Origin frames 1.27° × 0.85° at 1.48″ per pixel, so it fills 23% of the frame’s short side.

Longer subs

10 s auto subs (15 s with the Nebula Filter); manual 1 to 30 s on the alt-az mount, longer only with the EQ wedge, and 60 s and up needs the StarSense Autoguider too. Time for a solid image by sub length:

Sub length	Bortle 3	Bortle 5	Bortle 7
10 s	24 min146 subs	45 min271 subs	2 h 16 min816 subs
15 s	22 min90 subs	43 min173 subs	2 h 14 min537 subs
30 s	21 min42 subs	41 min83 subs	2 h 12 min265 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	24 min146 subs	45 min271 subs	2 h 16 min816 subs
dual-band (Nebula Filter), drawer	23 min138 subs	29 min176 subs	57 min343 subs

The Origin has no built-in dual-band filter. Filter drawer takes 1.25-inch or 2-inch filters, including dual-band; Celestron sells an optional Nebula Filter. On an emission target like this it is the single biggest upgrade you can make.

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 Celestron Origin

The first-generation Origin: a 6-inch f/2.2 RASA in a smart package and the fastest system here by a wide margin. Superseded by the Mark II in late 2025 and no longer sold new; Celestron offers a camera upgrade to the Mark II sensor.

10 s auto subs (15 s with the Nebula Filter); manual 1 to 30 s on the alt-az mount, longer only with the EQ wedge, and 60 s and up needs the StarSense Autoguider too. Filter drawer takes 1.25-inch or 2-inch filters, including dual-band; Celestron sells an optional Nebula Filter.

Longer subs matter most under dark skies, where read noise rather than skyglow sets the floor. From a city the difference between 10 s and 30 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.

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Imaged the Cocoon Nebula with your Origin? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Cocoon Nebula from a Origin? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the Cocoon Nebula · All targets for the Origin