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

About 1 h 12 min of total integration for a solid image, or 4 h 49 min for a showpiece. A quick look takes 18 min.

How many subs is that on the Vespera Pro?

At the default 10 s sub length, 434 subs for a solid image from Bortle 6 and 204 from Bortle 3.

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

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 1 h 12 min to 57 min.

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

From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 1 h 12 min (434 subs of 10 s) for a solid image of the Omega Nebula. A quick look takes 18 min; a showpiece 4 h 49 min. Under a Bortle 3 rural sky the solid figure drops to 34 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 11% of the frame’s short side.

Omega 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	8 min46 subs	30 min182 subs	2 h 01 min725 subs
Bortle 2Typical dark site	8 min48 subs	31 min189 subs	2 h 06 min756 subs
Bortle 3Rural	8 min51 subs	34 min204 subs	2 h 16 min815 subs
Bortle 4Rural / suburban transition	10 min60 subs	40 min240 subs	2 h 39 min957 subs
Bortle 5Suburban	12 min74 subs	49 min296 subs	3 h 17 min1,182 subs
Bortle 6Bright suburban	18 min109 subs	1 h 12 min434 subs	4 h 49 min1,736 subs
Bortle 7Suburban / urban transition	29 min175 subs	1 h 56 min698 subs	7 h 45 min2,790 subs
Bortle 8City	46 min277 subs	3 h 04 min1,107 subs	12 h4,427 subs
Bortle 9Inner city	1 h 22 min495 subs	5 h 30 min1,980 subs	22 h7,917 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 34 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.)

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How it frames

The Omega Nebula is 11′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 11% 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	34 min204 subs	49 min296 subs	1 h 56 min698 subs
20 s	29 min88 subs	44 min134 subs	1 h 51 min335 subs
30 s	27 min55 subs	43 min86 subs	1 h 50 min220 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	34 min204 subs	49 min296 subs	1 h 56 min698 subs
dual-band (Dual Band filter), clip-on	45 min270 subs	50 min298 subs	1 h 10 min421 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 Omega Nebula

A bright, compact swan-shaped emission nebula, one of the brightest in the sky per unit area. Excellent from suburban skies.

M17, NGC 6618, Swan Nebula · Emission nebula in Sagittarius · magnitude 6.0 · 11′ · best in Jun, Jul, Aug. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Emission nebulae glow in a few narrow lines, mostly hydrogen-alpha (deep red) and doubly ionised oxygen (teal). A dual-band filter passes those lines and blocks most skyglow, which is why it cuts the time needed from a suburban sky so dramatically. Use it. From a genuinely dark site the gain is smaller because there is less skyglow to block, and read noise becomes the limit, which is where longer subs (EQ mode, or Expert Mode on a Vespera) earn their keep.

Stars lose colour through a dual-band filter; a short broadband stack blended in fixes that if you care.

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 Omega 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 Omega 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 Omega Nebula · All targets for the Vespera Pro