How long should I image the M107 with the Vespera 3 from a Bortle 6 sky?

About 57 min of total integration for a solid image, or 3 h 46 min for a showpiece. A quick look takes 14 min.

How many subs is that on the Vespera 3?

At the default 10 s sub length, 340 subs for a solid image from Bortle 6 and 137 from Bortle 3.

Does a dual-band filter help on the M107?

No. The M107 is a broadband target and a dual-band filter blocks most of its light. Shoot without a filter.

How long to image the M107 with the Vaonis Vespera 3

From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 57 min (340 subs of 10 s) for a solid image of the M107. A quick look takes 14 min; a showpiece 3 h 46 min. Under a Bortle 3 rural sky the solid figure drops to 23 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 15% of the frame’s short side.

M107 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 min30 subs	19 min117 subs	1 h 18 min467 subs
Bortle 2Typical dark site	5 min31 subs	21 min124 subs	1 h 22 min494 subs
Bortle 3Rural	6 min35 subs	23 min137 subs	1 h 31 min546 subs
Bortle 4Rural / suburban transition	7 min42 subs	28 min168 subs	1 h 52 min672 subs
Bortle 5Suburban	9 min55 subs	36 min218 subs	2 h 25 min871 subs
Bortle 6Bright suburban	14 min85 subs	57 min340 subs	3 h 46 min1,359 subs
Bortle 7Suburban / urban transition	24 min144 subs	1 h 35 min573 subs	6 h 21 min2,289 subs
Bortle 8City	39 min234 subs	2 h 36 min934 subs	10 h3,734 subs
Bortle 9Inner city	1 h 11 min426 subs	4 h 44 min1,704 subs	19 h6,814 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 14 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 M107 is 13′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it fills 15% 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	23 min137 subs	36 min218 subs	1 h 35 min573 subs
20 s	20 min60 subs	33 min100 subs	1 h 32 min277 subs
30 s	19 min38 subs	32 min65 subs	1 h 31 min183 subs

About the M107

A loose, dust-dimmed globular in Ophiuchus. Modest but straightforward.

NGC 6171 · Globular cluster in Ophiuchus · magnitude 7.9 · 13′ · best in May, Jun, Jul. 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 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 M107 with your Vespera 3? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the M107 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 M107 · All targets for the Vespera 3