How long to image the M61 with the Vaonis Vespera Pro
From a Bortle 6 suburban sky, the Vaonis Vespera Pro needs about 6 h 59 min (2,517 subs of 10 s) for a solid image of the M61. A quick look takes 1 h 45 min; a showpiece 28 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 59 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.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 39 min234 subs | 2 h 35 min933 subs | 10 h3,729 subs |
| Bortle 2Typical dark site | 41 min246 subs | 2 h 43 min981 subs | 11 h3,923 subs |
| Bortle 3Rural | 45 min269 subs | 2 h 59 min1,073 subs | 12 h4,292 subs |
| Bortle 4Rural / suburban transition | 54 min324 subs | 3 h 36 min1,296 subs | 14 h5,184 subs |
| Bortle 5Suburban | 1 h 09 min413 subs | 4 h 35 min1,650 subs | 18 h6,597 subs |
| Bortle 6Bright suburban | 1 h 45 min630 subs | 6 h 59 min2,517 subs | 28 h10,066 subs |
| Bortle 7Suburban / urban transition | 2 h 54 min1,043 subs | 12 h4,169 subs | 46 h16,676 subs |
| Bortle 8City | 4 h 41 min1,684 subs | 19 h6,735 subs | 75 h26,939 subs |
| Bortle 9Inner city | 8 h 29 min3,052 subs | 34 h12,207 subs | 140+ h48,827 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 9 h 05 min of run time. That is more than one night: over 2 nights, about 4 h 33 min each. The Vespera Pro’s battery (rated about 11 h) should cover each night; 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 M61 is 6′ × 5.5′ 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 length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 2 h 59 min1,073 subs | 4 h 35 min1,650 subs | 12 h4,169 subs |
| 20 s | 2 h 29 min446 subs | 4 h 05 min734 subs | 11 h1,994 subs |
| 30 s | 2 h 18 min277 subs | 3 h 54 min469 subs | 11 h1,309 subs |
About the M61
A face-on barred spiral at the southern end of the Virgo cluster, with well-defined arms.
NGC 4303 · Galaxy in Virgo · magnitude 9.7 · 6′ × 5.5′ · best in Mar, Apr, May. 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 M61 from a Vespera Pro? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M61 with the ZWO Seestar S50: 3 h 07 min from Bortle 6
- M61 with the ZWO Seestar S50 Pro: 3 h 25 min from Bortle 6
- M61 with the ZWO Seestar S30: 3 h 17 min from Bortle 6
- M61 with the ZWO Seestar S30 Pro: 3 h 37 min from Bortle 6
- M61 with the DwarfLab DWARF 3: 4 h 32 min from Bortle 6
- M61 with the DwarfLab DWARF mini: 3 h 07 min from Bortle 6
- M61 with the DwarfLab Draco: 2 h 34 min from Bortle 6
- M61 with the DwarfLab DWARF II: 11 h from Bortle 6
- M61 with the Vaonis Vespera II: 3 h 07 min from Bortle 6
- M61 with the Vaonis Vespera 3: 2 h 59 min from Bortle 6
- M61 with the Vaonis Vespera Pro 2: 6 h 40 min from Bortle 6
- M61 with the Unistellar eQuinox 2: 2 h 50 min from Bortle 6
- M61 with the Unistellar Odyssey: 13 h from Bortle 6
- M61 with the Celestron Origin: 50 min from Bortle 6
- M61 with the Celestron Origin Mark II: 1 h 08 min from Bortle 6
All telescopes for the M61 · All targets for the Vespera Pro