How long to image the M66 with the Unistellar Odyssey

From a Bortle 6 suburban sky, the Unistellar Odyssey needs about 2 h 46 min (2,485 subs of 4 s) for a solid image of the M66. A quick look takes 41 min; a showpiece 11 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 53 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 27% of the frame’s short side.

M66 with the Unistellar Odyssey: 4 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site27 min406 subs1 h 48 min1,623 subs7 h 13 min6,489 subs
Bortle 2Typical dark site27 min413 subs1 h 50 min1,649 subs7 h 20 min6,595 subs
Bortle 3Rural28 min425 subs1 h 53 min1,699 subs7 h 33 min6,795 subs
Bortle 4Rural / suburban transition30 min456 subs2 h 01 min1,821 subs8 h 05 min7,281 subs
Bortle 5Suburban34 min504 subs2 h 14 min2,013 subs8 h 57 min8,051 subs
Bortle 6Bright suburban41 min622 subs2 h 46 min2,485 subs11 h9,940 subs
Bortle 7Suburban / urban transition56 min847 subs3 h 46 min3,385 subs15 h13,539 subs
Bortle 8City1 h 20 min1,196 subs5 h 19 min4,782 subs21 h19,128 subs
Bortle 9Inner city2 h 09 min1,941 subs8 h 37 min7,762 subs34 h31,046 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 3 h 35 min of run time. The Odyssey’s battery (rated about 5 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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Everything that fits the Odyssey →

How it frames

The M66 is 9′ × 4′ across. The Odyssey frames 0.75° × 0.56° at 0.93″ per pixel, so it fills 27% of the frame’s short side.

About the M66

The brightest of the Leo Triplet, with asymmetric arms from a past encounter.

NGC 3627 · Galaxy in Leo · magnitude 8.9 · 9′ × 4′ · best in Feb, Mar, Apr. 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 Unistellar Odyssey

Unistellar’s compact 85 mm with autofocus and tiny pixels. Sharp, but the fine sampling costs time on faint extended targets. The Odyssey Pro is the same telescope with an eyepiece added, so these figures apply to both.

Fixed 4 s subs in Enhanced Vision; they cannot be changed. No filter option; Unistellar says third-party filters cannot be fitted to the Odyssey.

The Odyssey uses fixed 4 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.

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Imaged the M66 with your Odyssey? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M66 from a Odyssey? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the M66 · All targets for the Odyssey