How long should I image the Owl Nebula with the Vespera 3 from a Bortle 6 sky?

About 51 min of total integration for a solid image, or 3 h 25 min for a showpiece. A quick look takes 13 min.

How many subs is that on the Vespera 3?

At the default 10 s sub length, 308 subs for a solid image from Bortle 6 and 134 from Bortle 3.

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

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 51 min to 36 min.

How long to image the Owl Nebula with the Vaonis Vespera 3

From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 51 min (308 subs of 10 s) for a solid image of the Owl Nebula. A quick look takes 13 min; a showpiece 3 h 25 min. Under a Bortle 3 rural sky the solid figure drops to 22 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 4% of the frame’s short side.

Owl Nebula with the Vaonis Vespera 3: 10 s subs.
Sky	Quick lookTarget obvious, still noisy	SolidClean enough to share	ShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site	5 min30 subs	19 min117 subs	1 h 18 min467 subs
Bortle 2Typical dark site	5 min31 subs	20 min123 subs	1 h 22 min490 subs
Bortle 3Rural	6 min34 subs	22 min134 subs	1 h 29 min535 subs
Bortle 4Rural / suburban transition	7 min41 subs	27 min161 subs	1 h 47 min642 subs
Bortle 5Suburban	8 min51 subs	34 min203 subs	2 h 15 min812 subs
Bortle 6Bright suburban	13 min77 subs	51 min308 subs	3 h 25 min1,229 subs
Bortle 7Suburban / urban transition	21 min127 subs	1 h 24 min506 subs	5 h 37 min2,023 subs
Bortle 8City	34 min204 subs	2 h 16 min815 subs	9 h 03 min3,257 subs
Bortle 9Inner city	1 h 01 min368 subs	4 h 05 min1,472 subs	16 h5,888 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 07 min of run time. The Vespera 3’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 30WVaonis says an external bank extends sessions; 30 W PD as for the II and Pro.
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How it frames

The Owl Nebula is 3.4′ × 3.3′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it fills 4% 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 widens the field to 4.3° × 2.4°. Time for a solid image by sub length:

Sub length	Bortle 3	Bortle 5	Bortle 7
10 s	22 min134 subs	34 min203 subs	1 h 24 min506 subs
20 s	20 min59 subs	31 min94 subs	1 h 22 min246 subs
30 s	19 min38 subs	30 min61 subs	1 h 21 min162 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	22 min134 subs	34 min203 subs	1 h 24 min506 subs
dual-band (Dual Band filter), clip-on	27 min163 subs	31 min184 subs	46 min277 subs

The Vespera 3 has no built-in dual-band filter. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar. The new optical baffle is not a substitute for a CLS filter. On an emission target like this it is the single biggest upgrade you can make.

About the Owl Nebula

A round planetary with two dark eyes. Large for its class and low in surface brightness; dual-band helps a lot.

M97, NGC 3587 · Planetary nebula in Ursa Major · magnitude 9.9 · 3.4′ × 3.3′ · best in Feb, Mar, Apr. 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 3

The 2026 Vespera: same 50 mm quadruplet class as the II on an 8 MP IMX585, with a 24 MP mosaic mode and 11 hours of battery. Per pixel it behaves like a Seestar S50 Pro without the built-in dual-band filter.

10 s subs by default; Expert Mode manual targets allow 1 to 30 s. Alt-azimuth only; CovalENS mosaic widens the field to 4.3° × 2.4°. Optional clip-on Vaonis filters: dual-band, light-pollution (CLS) and solar. The new optical baffle is not a substitute for a CLS filter.

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 3Vaonis 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 Owl Nebula with your Vespera 3? Did the solid figure match?Anonymous, one tap. It is how the model gets calibrated.

Have an image of the Owl Nebula from a Vespera 3? Email it with your total time and sky to [email protected] and it goes here, credited.

Same target, other telescopes

All telescopes for the Owl Nebula · All targets for the Vespera 3