How long should I image the Spindle Galaxy with the Vespera Pro 2 from a Bortle 6 sky?

About 50 min of total integration for a solid image, or 3 h 19 min for a showpiece. A quick look takes 12 min.

How many subs is that on the Vespera Pro 2?

At the default 10 s sub length, 300 subs for a solid image from Bortle 6 and 153 from Bortle 3.

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

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

How long to image the Spindle Galaxy with the Vaonis Vespera Pro 2

From a Bortle 6 suburban sky, the Vaonis Vespera Pro 2 needs about 50 min (300 subs of 10 s) for a solid image of the Spindle Galaxy. A quick look takes 12 min; a showpiece 3 h 19 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 5% of the frame’s short side.

Spindle Galaxy with the Vaonis Vespera Pro 2: 10 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	6 min35 subs	23 min139 subs	1 h 32 min553 subs
Bortle 2Typical dark site	6 min36 subs	24 min143 subs	1 h 35 min572 subs
Bortle 3Rural	6 min39 subs	25 min153 subs	1 h 42 min610 subs
Bortle 4Rural / suburban transition	7 min44 subs	29 min176 subs	1 h 57 min701 subs
Bortle 5Suburban	9 min53 subs	35 min211 subs	2 h 21 min844 subs
Bortle 6Bright suburban	12 min75 subs	50 min300 subs	3 h 19 min1,197 subs
Bortle 7Suburban / urban transition	19 min117 subs	1 h 18 min468 subs	5 h 11 min1,869 subs
Bortle 8City	30 min182 subs	2 h 01 min728 subs	8 h 05 min2,912 subs
Bortle 9Inner city	54 min322 subs	3 h 34 min1,285 subs	14 h5,137 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 05 min of run time. The Vespera Pro 2’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 30WExternal bank extends the 11 h battery.
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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 Spindle Galaxy is 4.7′ × 1.9′ across. The Vespera Pro 2 frames 1.65° × 1.65° at 1.68″ per pixel, so it fills 5% 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 gives 3.2° × 3.2° at 50 MP. Time for a solid image by sub length:

Sub length	Bortle 3	Bortle 5	Bortle 7
10 s	25 min153 subs	35 min211 subs	1 h 18 min468 subs
20 s	22 min68 subs	32 min97 subs	1 h 15 min225 subs
30 s	21 min43 subs	31 min63 subs	1 h 14 min148 subs

About the Spindle Galaxy

An edge-on lenticular with a thin dust lane. Small, but its surface brightness is decent.

M102, NGC 5866 · Galaxy in Draco · magnitude 9.9 · 4.7′ × 1.9′ · best in Apr, May, Jun. 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 Pro 2

The square-sensor 2026 Vespera with 2 µm pixels. Sharper than the Vespera 3 on small targets and correspondingly slower per pixel; the 12.5 MP square frame suits galaxies and planetaries.

10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only; CovalENS mosaic gives 3.2° × 3.2° at 50 MP. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar.

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 Pro 2Vaonis 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 Spindle Galaxy with your Vespera Pro 2? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Spindle Galaxy from a Vespera Pro 2? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the Spindle Galaxy · All targets for the Vespera Pro 2