How long should I image the M56 with the Vespera II from a Bortle 6 sky?

About 41 min of total integration for a solid image, or 2 h 43 min for a showpiece. A quick look takes 10 min.

How many subs is that on the Vespera II?

At the default 10 s sub length, 244 subs for a solid image from Bortle 6 and 107 from Bortle 3.

Does a dual-band filter help on the M56?

No. The M56 is a broadband target and a dual-band filter blocks most of its light. Shoot without a filter.

How long to image the M56 with the Vaonis Vespera II

From a Bortle 6 suburban sky, the Vaonis Vespera II needs about 41 min (244 subs of 10 s) for a solid image of the M56. A quick look takes 10 min; a showpiece 2 h 43 min. Under a Bortle 3 rural sky the solid figure drops to 18 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.

M56 with the Vaonis Vespera II: 10 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	4 min24 subs	16 min94 subs	1 h 02 min374 subs
Bortle 2Typical dark site	4 min25 subs	16 min98 subs	1 h 05 min392 subs
Bortle 3Rural	4 min27 subs	18 min107 subs	1 h 11 min427 subs
Bortle 4Rural / suburban transition	5 min32 subs	21 min128 subs	1 h 25 min512 subs
Bortle 5Suburban	7 min41 subs	27 min162 subs	1 h 48 min646 subs
Bortle 6Bright suburban	10 min61 subs	41 min244 subs	2 h 43 min976 subs
Bortle 7Suburban / urban transition	17 min101 subs	1 h 07 min401 subs	4 h 27 min1,603 subs
Bortle 8City	27 min162 subs	1 h 47 min645 subs	7 h 10 min2,578 subs
Bortle 9Inner city	49 min292 subs	3 h 14 min1,165 subs	13 h4,657 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 53 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.)

USB-C PD power bank 20000mAh 30WOnly four hours inside; Vaonis specifies a 30 W PD source. C-to-C cable not included.
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Vaonis Vespera hygrometer sensorTriggers the built-in demister automatically; the correct dew accessory for the II.
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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 M56 is 8.8′ across. The Vespera II frames 2.55° × 1.44° at 2.39″ 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 length	Bortle 3	Bortle 5	Bortle 7
10 s	18 min107 subs	27 min162 subs	1 h 07 min401 subs
20 s	16 min47 subs	25 min75 subs	1 h 05 min194 subs
30 s	15 min30 subs	24 min49 subs	1 h 04 min128 subs

About the M56

A small globular between Albireo and the Ring Nebula, set in a rich star field.

NGC 6779 · Globular cluster in Lyra · magnitude 8.3 · 8.8′ · best in Jun, Jul, Aug. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Globular clusters are point sources packed tight, so they come quickly: the core resolves into stars within a handful of minutes on any smart scope. More time deepens the halo and pulls in the faint outer members. Use short subs so the core does not saturate into a white blob, and no filter.

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 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 M56 with your Vespera II? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M56 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 M56 · All targets for the Vespera II