How long should I image the Ghost of Cassiopeia with the Origin Mark II from a Bortle 6 sky?

About 1 h 02 min of total integration for a solid image, or 4 h 07 min for a showpiece. A quick look takes 15 min.

How many subs is that on the Origin Mark II?

At the default 10 s sub length, 371 subs for a solid image from Bortle 6 and 112 from Bortle 3.

Does a dual-band filter help on the Ghost of Cassiopeia?

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 1 h 02 min to 28 min.

How long to image the Ghost of Cassiopeia with the Celestron Origin Mark II

From a Bortle 6 suburban sky, the Celestron Origin Mark II needs about 1 h 02 min (371 subs of 10 s) for a solid image of the Ghost of Cassiopeia. A quick look takes 15 min; a showpiece 4 h 07 min. Under a Bortle 3 rural sky the solid figure drops to 19 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 22% of the frame’s short side.

Ghost of Cassiopeia with the Celestron Origin Mark II: 10 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	4 min22 subs	14 min87 subs	58 min347 subs
Bortle 2Typical dark site	4 min24 subs	16 min96 subs	1 h 04 min382 subs
Bortle 3Rural	5 min28 subs	19 min112 subs	1 h 15 min448 subs
Bortle 4Rural / suburban transition	6 min38 subs	25 min152 subs	1 h 41 min608 subs
Bortle 5Suburban	9 min54 subs	36 min216 subs	2 h 23 min861 subs
Bortle 6Bright suburban	15 min93 subs	1 h 02 min371 subs	4 h 07 min1,481 subs
Bortle 7Suburban / urban transition	28 min167 subs	1 h 51 min666 subs	7 h 24 min2,663 subs
Bortle 8City	47 min282 subs	3 h 07 min1,125 subs	12 h4,499 subs
Bortle 9Inner city	1 h 28 min526 subs	5 h 51 min2,104 subs	23 h8,414 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 20 min of run time. The Origin Mark II’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 Ghost of Cassiopeia is 10′ × 3′ across. The Origin Mark II frames 1.32° × 0.75° at 1.23″ per pixel, so it fills 22% 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. Celestron warns the f/2.2 optics saturate quickly without the filter. Time for a solid image by sub length:

Sub length	Bortle 3	Bortle 5	Bortle 7
10 s	19 min112 subs	36 min216 subs	1 h 51 min666 subs
15 s	18 min74 subs	35 min142 subs	1 h 51 min443 subs
30 s	18 min36 subs	35 min71 subs	1 h 50 min221 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	19 min112 subs	36 min216 subs	1 h 51 min666 subs
dual-band (Nebula Filter), drawer	15 min91 subs	20 min122 subs	43 min260 subs

The Origin Mark II 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 Ghost of Cassiopeia

A small emission and reflection wisp being eroded by the star Gamma Cassiopeiae. Keep the bright star's glare under control.

IC 63 · Emission nebula in Cassiopeia · magnitude 10.0 · 10′ × 3′ · best in Sep, Oct, Nov. 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 Mark II

The Origin Mark II (late 2025): the same 6-inch f/2.2 RASA with an 8 MP IMX678 in place of the original 6 MP IMX178. Smaller pixels for finer detail, a quieter sensor, and still the fastest system here by a wide margin.

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 Ghost of Cassiopeia with your Origin Mark II? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Ghost of Cassiopeia from a Origin Mark 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 Ghost of Cassiopeia · All targets for the Origin Mark II