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

About 37 min of total integration for a solid image, or 2 h 26 min for a showpiece. A quick look takes 9 min.

How many subs is that on the Vespera 3?

At the default 10 s sub length, 220 subs for a solid image from Bortle 6 and 100 from Bortle 3.

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

Yes. It is an emission-line object; from Bortle 6 the filter cuts the solid-image time from 37 min to 26 min.

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

From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 37 min (220 subs of 10 s) for a solid image of the Crab Nebula. A quick look takes 9 min; a showpiece 2 h 26 min. Under a Bortle 3 rural sky the solid figure drops to 17 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 7% of the frame’s short side.

Crab 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	4 min22 subs	15 min88 subs	58 min351 subs
Bortle 2Typical dark site	4 min23 subs	15 min92 subs	1 h 01 min367 subs
Bortle 3Rural	4 min25 subs	17 min100 subs	1 h 06 min398 subs
Bortle 4Rural / suburban transition	5 min30 subs	20 min118 subs	1 h 19 min472 subs
Bortle 5Suburban	6 min37 subs	25 min148 subs	1 h 38 min590 subs
Bortle 6Bright suburban	9 min55 subs	37 min220 subs	2 h 26 min878 subs
Bortle 7Suburban / urban transition	15 min90 subs	59 min357 subs	3 h 58 min1,428 subs
Bortle 8City	24 min143 subs	1 h 35 min571 subs	6 h 20 min2,281 subs
Bortle 9Inner city	43 min257 subs	2 h 51 min1,026 subs	11 h4,102 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 48 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, and 30% off the battery for a December night.)

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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red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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hand warmers long lastingAir-activated packs give hours of heat for the person; winter nights are long and you spend most of them standing still.
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How it frames

The Crab Nebula is 6′ × 4′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it fills 7% 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	17 min100 subs	25 min148 subs	59 min357 subs
20 s	15 min45 subs	23 min69 subs	58 min174 subs
30 s	15 min30 subs	22 min45 subs	57 min115 subs

With and without the dual-band filter

Solid quality, default sub length.
Filter	Bortle 3	Bortle 5	Bortle 7
No filter	17 min100 subs	25 min148 subs	59 min357 subs
dual-band (Dual Band filter), clip-on	20 min123 subs	23 min137 subs	34 min202 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 Crab Nebula

The remains of the supernova of 1054, a tangle of filaments around a pulsar. Small but bright enough for a good result in an evening.

M1, NGC 1952 · Supernova remnant in Taurus · magnitude 8.4 · 6′ × 4′ · best in Nov, Dec, Jan. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

Supernova remnants are emission-line objects, strong in both hydrogen-alpha and OIII, and their filaments are thin, so pixel scale matters as much as aperture. A dual-band filter is essential from any lit sky and still helps under a dark one. These are long-integration targets; plan on several sessions and stack across nights.

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 Crab 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 Crab 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 Crab Nebula · All targets for the Vespera 3