How long to image the M65 with the Vaonis Vespera Pro

From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 1 h 56 min (697 subs of 10 s) for a solid image of the M65. A quick look takes 29 min; a showpiece 7 h 45 min. Under a Bortle 3 rural sky the solid figure drops to 53 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 10% of the frame’s short side.

M65 with the Vaonis Vespera Pro: 10 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site12 min70 subs47 min280 subs3 h 06 min1,117 subs
Bortle 2Typical dark site12 min73 subs49 min292 subs3 h 15 min1,168 subs
Bortle 3Rural13 min80 subs53 min317 subs3 h 31 min1,266 subs
Bortle 4Rural / suburban transition16 min94 subs1 h 03 min376 subs4 h 10 min1,501 subs
Bortle 5Suburban20 min118 subs1 h 18 min469 subs5 h 12 min1,874 subs
Bortle 6Bright suburban29 min175 subs1 h 56 min697 subs7 h 45 min2,788 subs
Bortle 7Suburban / urban transition47 min284 subs3 h 09 min1,133 subs13 h4,532 subs
Bortle 8City1 h 15 min453 subs5 h 02 min1,810 subs20 h7,238 subs
Bortle 9Inner city2 h 16 min814 subs9 h 02 min3,253 subs36 h13,010 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 2 h 31 min of run time. The Vespera Pro’s battery (rated about 11 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 M65 is 10′ × 3′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 10% of the frame’s short side.

Longer subs

10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only, no EQ mode. Time for a solid image by sub length:

Sub lengthBortle 3Bortle 5Bortle 7
10 s53 min317 subs1 h 18 min469 subs3 h 09 min1,133 subs
20 s45 min135 subs1 h 10 min211 subs3 h 01 min543 subs
30 s42 min85 subs1 h 07 min135 subs2 h 58 min357 subs

About the M65

One of the Leo Triplet, an inclined spiral with a bright core. Fits in a frame with M66 and NGC 3628.

NGC 3623 · Galaxy in Leo · magnitude 9.3 · 10′ × 3′ · 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 Vaonis Vespera Pro

The square-sensor Vespera with 2 µm pixels. Higher resolution than the II, and correspondingly slower per pixel: expect around double the time for the same per-pixel SNR. Run-out in 2026 and replaced by the Vespera Pro 2.

10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only, no EQ mode. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar.

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 M65 with your Vespera Pro? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M65 from a Vespera Pro? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the M65 · All targets for the Vespera Pro