How long to image the M87 with the Vaonis Vespera II

From a Bortle 6 suburban sky, the Vaonis Vespera II needs about 1 h 03 min (376 subs of 10 s) for a solid image of the M87. A quick look takes 16 min; a showpiece 4 h 10 min. Under a Bortle 3 rural sky the solid figure drops to 26 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 9% of the frame’s short side.

M87 with the Vaonis Vespera II: 10 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site6 min35 subs23 min138 subs1 h 32 min550 subs
Bortle 2Typical dark site6 min37 subs24 min145 subs1 h 36 min579 subs
Bortle 3Rural7 min40 subs26 min159 subs1 h 46 min635 subs
Bortle 4Rural / suburban transition8 min49 subs32 min193 subs2 h 08 min769 subs
Bortle 5Suburban10 min62 subs41 min246 subs2 h 44 min982 subs
Bortle 6Bright suburban16 min94 subs1 h 03 min376 subs4 h 10 min1,503 subs
Bortle 7Suburban / urban transition26 min157 subs1 h 44 min625 subs6 h 56 min2,498 subs
Bortle 8City42 min253 subs2 h 48 min1,011 subs11 h4,042 subs
Bortle 9Inner city1 h 16 min459 subs5 h 06 min1,834 subs20 h7,335 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 21 min of run time. The Vespera II’s battery (rated about 4 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.)

Affiliate links: the retailer pays us a small commission and you pay the same price. These are search links to the named product, not endorsements of a particular listing; check the listing matches your model.

Everything that fits the Vespera II →

How it frames

The M87 is 8′ × 7′ across. The Vespera II frames 2.55° × 1.44° at 2.39″ per pixel, so it fills 9% 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 s26 min159 subs41 min246 subs1 h 44 min625 subs
20 s23 min70 subs37 min113 subs1 h 41 min303 subs
30 s22 min44 subs36 min73 subs1 h 40 min200 subs

About the M87

The supergiant elliptical at the heart of the Virgo cluster, home of the first-photographed black hole. Bright, round, structureless.

NGC 4486, Virgo A · Galaxy in Virgo · magnitude 8.6 · 8′ × 7′ · best in Mar, Apr, May. 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 II

A 50 mm quadruplet on an 8 MP sensor with Vaonis’s mosaic mode for wide fields. Same optics class as the Seestar S50, four times the pixels.

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; the app detects which is fitted.

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 Vespera IIVaonis store DirectAmazon UKAmazon USThe Vaonis 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 M87 with your Vespera II? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M87 from a Vespera 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 M87 · All targets for the Vespera II