How long should I image the Dumbbell Nebula with the Vespera Pro from a Bortle 6 sky?

About 1 h of total integration for a solid image, or 4 h for a showpiece. A quick look takes 15 min.

How many subs is that on the Vespera Pro?

At the default 10 s sub length, 361 subs for a solid image from Bortle 6 and 178 from Bortle 3.

Does a dual-band filter help on the Dumbbell Nebula?

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 1 h to 49 min.

How long to image the Dumbbell Nebula with the Vaonis Vespera Pro

From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 1 h (361 subs of 10 s) for a solid image of the Dumbbell Nebula. A quick look takes 15 min; a showpiece 4 h. Under a Bortle 3 rural sky the solid figure drops to 30 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 8% of the frame’s short side.

Dumbbell Nebula with the Vaonis Vespera Pro: 10 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	7 min41 subs	27 min161 subs	1 h 47 min641 subs
Bortle 2Typical dark site	7 min42 subs	28 min167 subs	1 h 51 min665 subs
Bortle 3Rural	7 min45 subs	30 min178 subs	1 h 59 min712 subs
Bortle 4Rural / suburban transition	9 min52 subs	34 min206 subs	2 h 17 min824 subs
Bortle 5Suburban	10 min63 subs	42 min251 subs	2 h 47 min1,003 subs
Bortle 6Bright suburban	15 min91 subs	1 h361 subs	4 h1,441 subs
Bortle 7Suburban / urban transition	24 min143 subs	1 h 35 min569 subs	6 h 19 min2,275 subs
Bortle 8City	37 min224 subs	2 h 29 min893 subs	9 h 55 min3,570 subs
Bortle 9Inner city	1 h 06 min396 subs	4 h 24 min1,583 subs	18 h6,332 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 18 min of run time. The Vespera Pro’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 30WExtends the 11 h battery; 30 W PD per Vaonis.
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How it frames

The Dumbbell Nebula is 8′ × 5.7′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 8% 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	30 min178 subs	42 min251 subs	1 h 35 min569 subs
20 s	26 min78 subs	38 min114 subs	1 h 31 min273 subs
30 s	25 min50 subs	37 min74 subs	1 h 30 min180 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	30 min178 subs	42 min251 subs	1 h 35 min569 subs
dual-band (Dual Band filter), clip-on	39 min237 subs	43 min260 subs	59 min357 subs

The Vespera Pro has no built-in dual-band filter. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar. On an emission target like this it is the single biggest upgrade you can make.

About the Dumbbell Nebula

The biggest, brightest planetary nebula for northern observers. Bright enough to look good in twenty minutes, and dual-band brings out the outer shell.

M27, NGC 6853 · Planetary nebula in Vulpecula · magnitude 7.4 · 8′ × 5.7′ · best in Jun, Jul, Aug. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Planetary nebulae are small but intensely bright per pixel in OIII and H-alpha, so they respond very well to a dual-band filter and do not need much time for the main shell. The faint outer halos most of them have are a different proposition and need hours. Keep subs short if the central region saturates.

About the Vaonis Vespera Pro

The square-sensor Vespera with 2 µm pixels. Higher resolution than the II, and correspondingly slower per pixel: expect around double the time for the same per-pixel SNR. Run-out in 2026 and replaced by the Vespera Pro 2.

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.

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.

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Imaged the Dumbbell Nebula with your Vespera Pro? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

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

Same target, other telescopes

All telescopes for the Dumbbell Nebula · All targets for the Vespera Pro