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

About 3 h 33 min of total integration for a solid image, or 14 h for a showpiece. A quick look takes 53 min.

How many subs is that on the Vespera Pro?

At the default 10 s sub length, 1,278 subs for a solid image from Bortle 6 and 541 from Bortle 3.

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

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 3 h 33 min to 2 h 35 min.

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

From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 3 h 33 min (1,278 subs of 10 s) for a solid image of the Eagle Nebula. A quick look takes 53 min; a showpiece 14 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 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 36% of the frame’s short side.

Eagle 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	20 min118 subs	1 h 18 min469 subs	5 h 12 min1,874 subs
Bortle 2Typical dark site	21 min124 subs	1 h 22 min494 subs	5 h 29 min1,974 subs
Bortle 3Rural	23 min136 subs	1 h 30 min541 subs	6 h2,162 subs
Bortle 4Rural / suburban transition	27 min164 subs	1 h 49 min655 subs	7 h 16 min2,617 subs
Bortle 5Suburban	35 min209 subs	2 h 19 min835 subs	9 h 16 min3,339 subs
Bortle 6Bright suburban	53 min320 subs	3 h 33 min1,278 subs	14 h5,110 subs
Bortle 7Suburban / urban transition	1 h 28 min531 subs	5 h 53 min2,121 subs	24 h8,484 subs
Bortle 8City	2 h 23 min858 subs	9 h 32 min3,431 subs	38 h13,724 subs
Bortle 9Inner city	4 h 19 min1,557 subs	17 h6,225 subs	69 h24,897 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 4 h 37 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 Eagle Nebula is 35′ × 28′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 36% 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	1 h 30 min541 subs	2 h 19 min835 subs	5 h 53 min2,121 subs
20 s	1 h 15 min224 subs	2 h 04 min371 subs	5 h 38 min1,015 subs
30 s	1 h 09 min139 subs	1 h 58 min237 subs	5 h 33 min666 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	1 h 30 min541 subs	2 h 19 min835 subs	5 h 53 min2,121 subs
dual-band (Dual Band filter), clip-on	1 h 57 min703 subs	2 h 12 min793 subs	3 h 18 min1,187 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 Eagle Nebula

Home of the Pillars of Creation. The cluster comes fast; the pillars and surrounding nebulosity need a dual-band filter and patience.

M16, NGC 6611, IC 4703 · Emission nebula in Serpens · magnitude 6.0 · 35′ × 28′ · 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 Eagle 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 Eagle 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 Eagle Nebula · All targets for the Vespera Pro