How long to image the M66 with the Vaonis Vespera Pro
From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 1 h 31 min (548 subs of 10 s) for a solid image of the M66. A quick look takes 23 min; a showpiece 6 h 05 min. Under a Bortle 3 rural sky the solid figure drops to 43 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 9% of the frame’s short side.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 9 min57 subs | 38 min228 subs | 2 h 32 min912 subs |
| Bortle 2Typical dark site | 10 min60 subs | 40 min238 subs | 2 h 38 min951 subs |
| Bortle 3Rural | 11 min65 subs | 43 min257 subs | 2 h 51 min1,026 subs |
| Bortle 4Rural / suburban transition | 13 min76 subs | 50 min302 subs | 3 h 21 min1,206 subs |
| Bortle 5Suburban | 16 min94 subs | 1 h 02 min373 subs | 4 h 08 min1,491 subs |
| Bortle 6Bright suburban | 23 min137 subs | 1 h 31 min548 subs | 6 h 05 min2,192 subs |
| Bortle 7Suburban / urban transition | 37 min221 subs | 2 h 27 min882 subs | 9 h 48 min3,527 subs |
| Bortle 8City | 58 min350 subs | 3 h 53 min1,400 subs | 16 h5,599 subs |
| Bortle 9Inner city | 1 h 44 min627 subs | 6 h 57 min2,505 subs | 28 h10,019 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 59 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.)
- USB-C PD power bank 20000mAh 30WExtends the 11 h battery; 30 W PD per Vaonis.
- red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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 M66 is 9′ × 4′ across. The Vespera Pro frames 1.62° × 1.62° at 1.65″ per pixel, so it fills 9% 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 | 43 min257 subs | 1 h 02 min373 subs | 2 h 27 min882 subs |
| 20 s | 37 min110 subs | 56 min169 subs | 2 h 21 min423 subs |
| 30 s | 35 min70 subs | 54 min108 subs | 2 h 19 min278 subs |
About the M66
The brightest of the Leo Triplet, with asymmetric arms from a past encounter.
NGC 3627 · Galaxy in Leo · magnitude 8.9 · 9′ × 4′ · best in Feb, Mar, Apr. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.
Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.
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.
Have an image of the M66 from a Vespera Pro? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M66 with the ZWO Seestar S50: 41 min from Bortle 6
- M66 with the ZWO Seestar S50 Pro: 45 min from Bortle 6
- M66 with the ZWO Seestar S30: 43 min from Bortle 6
- M66 with the ZWO Seestar S30 Pro: 47 min from Bortle 6
- M66 with the DwarfLab DWARF 3: 1 h from Bortle 6
- M66 with the DwarfLab DWARF mini: 41 min from Bortle 6
- M66 with the DwarfLab Draco: 34 min from Bortle 6
- M66 with the DwarfLab DWARF II: 2 h 18 min from Bortle 6
- M66 with the Vaonis Vespera II: 41 min from Bortle 6
- M66 with the Vaonis Vespera 3: 39 min from Bortle 6
- M66 with the Vaonis Vespera Pro 2: 1 h 27 min from Bortle 6
- M66 with the Unistellar eQuinox 2: 36 min from Bortle 6
- M66 with the Unistellar Odyssey: 2 h 46 min from Bortle 6
- M66 with the Celestron Origin: 11 min from Bortle 6
- M66 with the Celestron Origin Mark II: 15 min from Bortle 6
All telescopes for the M66 · All targets for the Vespera Pro