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

About 26 min of total integration for a solid image, or 1 h 45 min for a showpiece. A quick look takes 7 min.

How many subs is that on the Vespera 3?

At the default 10 s sub length, 158 subs for a solid image from Bortle 6 and 75 from Bortle 3.

Does a dual-band filter help on the Bow-Tie Nebula?

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 26 min to 20 min.

How long to image the Bow-Tie Nebula with the Vaonis Vespera 3

From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 26 min (158 subs of 10 s) for a solid image of the Bow-Tie Nebula. A quick look takes 7 min; a showpiece 1 h 45 min. Under a Bortle 3 rural sky the solid figure drops to 12 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 is small in the frame, about 20 pixels across.

Bow-Tie 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	3 min17 subs	11 min67 subs	44 min267 subs
Bortle 2Typical dark site	3 min18 subs	12 min70 subs	46 min278 subs
Bortle 3Rural	3 min19 subs	12 min75 subs	50 min299 subs
Bortle 4Rural / suburban transition	4 min22 subs	15 min88 subs	58 min350 subs
Bortle 5Suburban	4 min27 subs	18 min108 subs	1 h 12 min432 subs
Bortle 6Bright suburban	7 min40 subs	26 min158 subs	1 h 45 min631 subs
Bortle 7Suburban / urban transition	11 min64 subs	42 min253 subs	2 h 48 min1,011 subs
Bortle 8City	17 min101 subs	1 h 07 min401 subs	4 h 27 min1,602 subs
Bortle 9Inner city	30 min179 subs	1 h 59 min716 subs	7 h 57 min2,861 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 34 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 Bow-Tie Nebula is 0.8′ × 0.6′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it is small in the frame, about 20 pixels across. It is worth doing, but the result is a crop rather than a full frame; a longer focal length would resolve more of it.

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	12 min75 subs	18 min108 subs	42 min253 subs
20 s	11 min34 subs	17 min51 subs	41 min123 subs
30 s	15 min30 subs	16 min33 subs	40 min81 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	12 min75 subs	18 min108 subs	42 min253 subs
dual-band (Dual Band filter), clip-on	15 min93 subs	17 min104 subs	25 min148 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 Bow-Tie Nebula

A red-tinged planetary near the pole with a bright central star. Small; dual-band brings out the bow.

NGC 40, Caldwell 2 · Planetary nebula in Cepheus · magnitude 11.6 · 0.8′ × 0.6′ · best in Sep, Oct, Nov. 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.

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Imaged the Bow-Tie 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 Bow-Tie 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 Bow-Tie Nebula · All targets for the Vespera 3