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

From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 1 h 25 min (511 subs of 10 s) for a solid image of the Crab Nebula. A quick look takes 21 min; a showpiece 5 h 40 min. Under a Bortle 3 rural sky the solid figure drops to 41 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 6% of the frame’s short side.

Crab Nebula with the Vaonis Vespera Pro: 10 s subs.
SkyQuick lookTarget obvious, still noisySolidClean enough to shareShowpieceSmooth faint detail, print-worthy
Bortle 1Excellent dark site9 min56 subs37 min223 subs2 h 28 min889 subs
Bortle 2Typical dark site10 min58 subs39 min232 subs2 h 34 min925 subs
Bortle 3Rural10 min62 subs41 min248 subs2 h 45 min992 subs
Bortle 4Rural / suburban transition12 min73 subs48 min289 subs3 h 12 min1,154 subs
Bortle 5Suburban15 min89 subs59 min353 subs3 h 55 min1,411 subs
Bortle 6Bright suburban21 min128 subs1 h 25 min511 subs5 h 40 min2,043 subs
Bortle 7Suburban / urban transition34 min203 subs2 h 15 min812 subs9 h 01 min3,246 subs
Bortle 8City53 min320 subs3 h 33 min1,279 subs14 h5,114 subs
Bortle 9Inner city1 h 35 min569 subs6 h 19 min2,275 subs25 h9,099 subs

Adjust in the calculator

Power and kit for this session

Allowing for slewing, focusing and rejected subs, that is about 1 h 51 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, and 30% off the battery for a December night.)

Affiliate links: the retailer pays us a small commission and you pay the same price. These are search links to the named product, not endorsements of a particular listing; check the listing matches your model.

Everything that fits the Vespera Pro →

How it frames

The Crab Nebula is 6′ × 4′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 6% 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 lengthBortle 3Bortle 5Bortle 7
10 s41 min248 subs59 min353 subs2 h 15 min812 subs
20 s36 min108 subs53 min160 subs2 h 10 min390 subs
30 s34 min68 subs51 min103 subs2 h 08 min256 subs

With and without the dual-band filter

Solid quality, default sub length.
FilterBortle 3Bortle 5Bortle 7
No filter41 min248 subs59 min353 subs2 h 15 min812 subs
dual-band (Dual Band filter), clip-on55 min330 subs1 h362 subs1 h 24 min502 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 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 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.

Where to buy the Vespera ProAmazon UKAmazon USAffiliate links: As an Amazon Associate I earn from qualifying purchases, at no cost to you.
Imaged the Crab 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 Crab 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 Crab Nebula · All targets for the Vespera Pro