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

About 1 h 34 min of total integration for a solid image, or 6 h 17 min for a showpiece. A quick look takes 24 min.

How many subs is that on the Vespera 3?

At the default 10 s sub length, 567 subs for a solid image from Bortle 6 and 219 from Bortle 3.

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

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

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

From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 1 h 34 min (567 subs of 10 s) for a solid image of the Sunflower Galaxy. A quick look takes 24 min; a showpiece 6 h 17 min. Under a Bortle 3 rural sky the solid figure drops to 36 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 14% of the frame’s short side.

Sunflower 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	8 min47 subs	31 min185 subs	2 h 03 min739 subs
Bortle 2Typical dark site	8 min50 subs	33 min197 subs	2 h 11 min786 subs
Bortle 3Rural	9 min55 subs	36 min219 subs	2 h 26 min874 subs
Bortle 4Rural / suburban transition	11 min69 subs	45 min273 subs	3 h 01 min1,089 subs
Bortle 5Suburban	15 min90 subs	1 h358 subs	3 h 58 min1,430 subs
Bortle 6Bright suburban	24 min142 subs	1 h 34 min567 subs	6 h 17 min2,265 subs
Bortle 7Suburban / urban transition	40 min242 subs	2 h 41 min965 subs	11 h3,857 subs
Bortle 8City	1 h 06 min396 subs	4 h 24 min1,582 subs	18 h6,328 subs
Bortle 9Inner city	2 h 01 min725 subs	8 h 03 min2,900 subs	32 h11,598 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 2 h 03 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 Sunflower Galaxy is 12.6′ × 7.2′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it fills 14% 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	36 min219 subs	1 h358 subs	2 h 41 min965 subs
20 s	31 min94 subs	54 min164 subs	2 h 35 min467 subs
30 s	29 min59 subs	53 min106 subs	2 h 34 min308 subs

About the Sunflower Galaxy

A flocculent spiral whose arms break into patches like sunflower seeds. Bright core, subtle outer disc.

M63, NGC 5055 · Galaxy in Canes Venatici · magnitude 8.6 · 12.6′ × 7.2′ · 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 Sunflower 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 Sunflower 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 Sunflower Galaxy · All targets for the Vespera 3