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

About 6 h 03 min of total integration for a solid image, or 24 h for a showpiece. A quick look takes 1 h 31 min.

How many subs is that on the Vespera Pro?

At the default 10 s sub length, 2,177 subs for a solid image from Bortle 6 and 897 from Bortle 3.

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

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 6 h 03 min to 4 h 19 min.

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

From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 6 h 03 min (2,177 subs of 10 s) for a solid image of the Pacman Nebula. A quick look takes 1 h 31 min; a showpiece 24 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 29 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.

Pacman 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	32 min193 subs	2 h 09 min772 subs	8 h 34 min3,086 subs
Bortle 2Typical dark site	34 min204 subs	2 h 16 min815 subs	9 h 03 min3,258 subs
Bortle 3Rural	37 min225 subs	2 h 29 min897 subs	9 h 57 min3,585 subs
Bortle 4Rural / suburban transition	46 min274 subs	3 h 02 min1,094 subs	12 h4,376 subs
Bortle 5Suburban	59 min352 subs	3 h 55 min1,408 subs	16 h5,631 subs
Bortle 6Bright suburban	1 h 31 min545 subs	6 h 03 min2,177 subs	24 h8,708 subs
Bortle 7Suburban / urban transition	2 h 32 min911 subs	10 h3,643 subs	40 h14,572 subs
Bortle 8City	4 h 07 min1,480 subs	16 h5,920 subs	66 h23,677 subs
Bortle 9Inner city	7 h 29 min2,694 subs	30 h10,774 subs	120+ h43,095 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 7 h 52 min of run time. That is more than one night: over 2 nights, about 3 h 56 min each. The Vespera Pro’s battery (rated about 11 h) should cover each night; 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 Pacman Nebula is 35′ × 30′ 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	2 h 29 min897 subs	3 h 55 min1,408 subs	10 h3,643 subs
20 s	2 h 02 min368 subs	3 h 28 min624 subs	9 h 40 min1,741 subs
30 s	1 h 54 min228 subs	3 h 19 min398 subs	9 h 31 min1,143 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	2 h 29 min897 subs	3 h 55 min1,408 subs	10 h3,643 subs
dual-band (Dual Band filter), clip-on	3 h 13 min1,160 subs	3 h 39 min1,317 subs	5 h 33 min2,001 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 Pacman Nebula

A bright emission nebula with a dark lane biting into it. Compact, bright, and excellent with a dual-band filter from suburban skies.

NGC 281 · Emission nebula in Cassiopeia · magnitude 7.4 · 35′ × 30′ · best in Sep, Oct, Nov. 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 Pacman 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 Pacman 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 Pacman Nebula · All targets for the Vespera Pro