How long to image the Fireworks Galaxy with the Vaonis Vespera 3
From a Bortle 6 suburban sky, the Vaonis Vespera 3 needs about 5 h 01 min (1,808 subs of 10 s) for a solid image of the Fireworks Galaxy. A quick look takes 1 h 15 min; a showpiece 20 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 49 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 13% 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 | 23 min136 subs | 1 h 30 min542 subs | 6 h 01 min2,167 subs |
| Bortle 2Typical dark site | 24 min146 subs | 1 h 37 min581 subs | 6 h 27 min2,323 subs |
| Bortle 3Rural | 27 min164 subs | 1 h 49 min655 subs | 7 h 16 min2,617 subs |
| Bortle 4Rural / suburban transition | 35 min209 subs | 2 h 19 min833 subs | 9 h 15 min3,329 subs |
| Bortle 5Suburban | 46 min279 subs | 3 h 06 min1,115 subs | 12 h4,459 subs |
| Bortle 6Bright suburban | 1 h 15 min452 subs | 5 h 01 min1,808 subs | 20 h7,229 subs |
| Bortle 7Suburban / urban transition | 2 h 10 min782 subs | 8 h 41 min3,128 subs | 35 h12,509 subs |
| Bortle 8City | 3 h 36 min1,295 subs | 14 h5,177 subs | 58 h20,707 subs |
| Bortle 9Inner city | 6 h 38 min2,387 subs | 27 h9,548 subs | 110+ h38,190 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 6 h 32 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.
- red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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How it frames
The Fireworks Galaxy is 11′ × 10′ across. The Vespera 3 frames 2.60° × 1.46° at 2.44″ per pixel, so it fills 13% 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 | 1 h 49 min655 subs | 3 h 06 min1,115 subs | 8 h 41 min3,128 subs |
| 20 s | 1 h 32 min276 subs | 2 h 48 min506 subs | 8 h 24 min1,512 subs |
| 30 s | 1 h 26 min172 subs | 2 h 43 min326 subs | 8 h 18 min997 subs |
About the Fireworks Galaxy
A face-on spiral famous for its supernovae, dimmed by Milky Way dust. Faint arms; the open cluster NGC 6939 sits nearby.
NGC 6946, Caldwell 12 · Galaxy in Cygnus · magnitude 9.6 · 11′ × 10′ · best in Jul, Aug, Sep. 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 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.
Have an image of the Fireworks Galaxy from a Vespera 3? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Fireworks Galaxy with the ZWO Seestar S50: 5 h 15 min from Bortle 6
- Fireworks Galaxy with the ZWO Seestar S50 Pro: 5 h 45 min from Bortle 6
- Fireworks Galaxy with the ZWO Seestar S30: 5 h 32 min from Bortle 6
- Fireworks Galaxy with the ZWO Seestar S30 Pro: 6 h 06 min from Bortle 6
- Fireworks Galaxy with the DwarfLab DWARF 3: 7 h 37 min from Bortle 6
- Fireworks Galaxy with the DwarfLab DWARF mini: 5 h 14 min from Bortle 6
- Fireworks Galaxy with the DwarfLab Draco: 4 h 19 min from Bortle 6
- Fireworks Galaxy with the DwarfLab DWARF II: 18 h from Bortle 6
- Fireworks Galaxy with the Vaonis Vespera II: 5 h 15 min from Bortle 6
- Fireworks Galaxy with the Vaonis Vespera Pro: 12 h from Bortle 6
- Fireworks Galaxy with the Vaonis Vespera Pro 2: 11 h from Bortle 6
- Fireworks Galaxy with the Unistellar eQuinox 2: 4 h 49 min from Bortle 6
- Fireworks Galaxy with the Unistellar Odyssey: 22 h from Bortle 6
- Fireworks Galaxy with the Celestron Origin: 1 h 23 min from Bortle 6
- Fireworks Galaxy with the Celestron Origin Mark II: 1 h 54 min from Bortle 6
All telescopes for the Fireworks Galaxy · All targets for the Vespera 3