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

About 28 min of total integration for a solid image, or 1 h 51 min for a showpiece. A quick look takes 7 min.

How many subs is that on the Vespera 3?

At the default 10 s sub length, 168 subs for a solid image from Bortle 6 and 72 from Bortle 3.

Does a dual-band filter help on the Sculptor Galaxy?

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

How long to image the Sculptor Galaxy with the Vaonis Vespera 3

From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 28 min (168 subs of 10 s) for a solid image of the Sculptor Galaxy. A quick look takes 7 min; a showpiece 1 h 51 min. Under a Bortle 3 rural sky the solid figure drops to 12 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 31% of the frame’s short side.

Sculptor Galaxy 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	3 min16 subs	10 min62 subs	41 min247 subs
Bortle 2Typical dark site	3 min17 subs	11 min65 subs	43 min260 subs
Bortle 3Rural	3 min18 subs	12 min72 subs	47 min285 subs
Bortle 4Rural / suburban transition	4 min22 subs	14 min86 subs	57 min344 subs
Bortle 5Suburban	5 min28 subs	18 min110 subs	1 h 13 min438 subs
Bortle 6Bright suburban	7 min42 subs	28 min168 subs	1 h 51 min669 subs
Bortle 7Suburban / urban transition	12 min70 subs	46 min278 subs	3 h 05 min1,109 subs
Bortle 8City	19 min113 subs	1 h 15 min449 subs	4 h 59 min1,793 subs
Bortle 9Inner city	34 min204 subs	2 h 15 min813 subs	9 h 02 min3,250 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 36 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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How it frames

The Sculptor Galaxy is 27′ × 7′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it fills 31% 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	12 min72 subs	18 min110 subs	46 min278 subs
20 s	10 min32 subs	17 min51 subs	45 min135 subs
30 s	15 min30 subs	16 min33 subs	44 min89 subs

About the Sculptor Galaxy

A big, dusty, nearly edge-on starburst galaxy, superb from the south and low but possible from mid-northern latitudes.

NGC 253, Caldwell 65, Silver Coin · Galaxy in Sculptor · magnitude 7.2 · 27′ × 7′ · best in Sep, Oct, Nov. 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 Sculptor Galaxy with your Vespera 3? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Sculptor Galaxy 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 Sculptor Galaxy · All targets for the Vespera 3