How long should I image the Spindle Galaxy with the Origin Mark II from a Bortle 6 sky?

About 9 min of total integration for a solid image, or 35 min for a showpiece. A quick look takes 2 min.

How many subs is that on the Origin Mark II?

At the default 10 s sub length, 53 subs for a solid image from Bortle 6 and 30 from Bortle 3.

Does a dual-band filter help on the Spindle Galaxy?

No. The Spindle Galaxy is a broadband target and a dual-band filter blocks most of its light. Shoot without a filter.

How long to image the Spindle Galaxy with the Celestron Origin Mark II

From a Bortle 6 suburban sky, the Celestron Origin Mark II needs about 9 min (53 subs of 10 s) for a solid image of the Spindle Galaxy. A quick look takes 2 min; a showpiece 35 min. Under a Bortle 3 rural sky the solid figure drops to 5 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 11% of the frame’s short side.

Spindle Galaxy 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	2 min10 subs	5 min30 subs	15 min90 subs
Bortle 2Typical dark site	2 min10 subs	5 min30 subs	15 min90 subs
Bortle 3Rural	2 min10 subs	5 min30 subs	15 min91 subs
Bortle 4Rural / suburban transition	2 min10 subs	5 min30 subs	18 min110 subs
Bortle 5Suburban	2 min10 subs	6 min35 subs	23 min139 subs
Bortle 6Bright suburban	2 min14 subs	9 min53 subs	35 min210 subs
Bortle 7Suburban / urban transition	4 min22 subs	14 min87 subs	58 min346 subs
Bortle 8City	6 min35 subs	23 min140 subs	1 h 33 min557 subs
Bortle 9Inner city	10 min63 subs	42 min252 subs	2 h 48 min1,007 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 11 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 Spindle Galaxy is 4.7′ × 1.9′ across. The Origin Mark II frames 1.32° × 0.75° at 1.23″ per pixel, so it fills 11% 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	5 min30 subs	6 min35 subs	14 min87 subs
15 s	8 min30 subs	8 min30 subs	14 min58 subs
30 s	15 min30 subs	15 min30 subs	15 min30 subs

About the Spindle Galaxy

An edge-on lenticular with a thin dust lane. Small, but its surface brightness is decent.

M102, NGC 5866 · Galaxy in Draco · magnitude 9.9 · 4.7′ × 1.9′ · best in Apr, May, Jun. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.

Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.

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.

Where to buy the Origin Mark IICelestron store Direct Amazon UK Amazon USThe Celestron store link is a plain link; the others are affiliate links. As an Amazon Associate I earn from qualifying purchases, at no cost to you.

Imaged the Spindle Galaxy 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 Spindle Galaxy 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 Spindle Galaxy · All targets for the Origin Mark II