How long should I image the M87 with the Vespera 3 from a Bortle 6 sky?

About 1 h of total integration for a solid image, or 3 h 59 min for a showpiece. A quick look takes 15 min.

How many subs is that on the Vespera 3?

At the default 10 s sub length, 360 subs for a solid image from Bortle 6 and 151 from Bortle 3.

Does a dual-band filter help on the M87?

No. The M87 is a broadband target and a dual-band filter blocks most of its light. Shoot without a filter.

How long to image the M87 with the Vaonis Vespera 3

From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 1 h (360 subs of 10 s) for a solid image of the M87. A quick look takes 15 min; a showpiece 3 h 59 min. Under a Bortle 3 rural sky the solid figure drops to 25 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 3: 10 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	5 min33 subs	22 min131 subs	1 h 27 min521 subs
Bortle 2Typical dark site	6 min35 subs	23 min138 subs	1 h 31 min549 subs
Bortle 3Rural	6 min38 subs	25 min151 subs	1 h 40 min602 subs
Bortle 4Rural / suburban transition	8 min46 subs	30 min183 subs	2 h 02 min731 subs
Bortle 5Suburban	10 min59 subs	39 min234 subs	2 h 36 min935 subs
Bortle 6Bright suburban	15 min90 subs	1 h360 subs	3 h 59 min1,437 subs
Bortle 7Suburban / urban transition	25 min150 subs	1 h 40 min598 subs	6 h 39 min2,392 subs
Bortle 8City	40 min243 subs	2 h 41 min969 subs	11 h3,875 subs
Bortle 9Inner city	1 h 13 min440 subs	4 h 53 min1,760 subs	20 h7,038 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 18 min of run time. The Vespera 3’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.)

USB-C PD power bank 20000mAh 30WVaonis says an external bank extends sessions; 30 W PD as for the II and Pro.
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red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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How it frames

The M87 is 8′ × 7′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ 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; CovalENS mosaic widens the field to 4.3° × 2.4°. Time for a solid image by sub length:

Sub length	Bortle 3	Bortle 5	Bortle 7
10 s	25 min151 subs	39 min234 subs	1 h 40 min598 subs
20 s	22 min66 subs	36 min108 subs	1 h 37 min290 subs
30 s	21 min42 subs	35 min70 subs	1 h 35 min191 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 3

The 2026 Vespera: same 50 mm quadruplet class as the II on an 8 MP IMX585, with a 24 MP mosaic mode and 11 hours of battery. Per pixel it behaves like a Seestar S50 Pro without the built-in dual-band filter.

10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only; CovalENS mosaic widens the field to 4.3° × 2.4°. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar. The new optical baffle is not a substitute for a CLS filter.

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 3Vaonis store Direct Amazon UK Amazon 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 3? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M87 from a Vespera 3? 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 3