How long to image the M49 with the ZWO Seestar S50
From a Bortle 6 suburban sky, the ZWO Seestar S50 needs about 1 h 09 min (416 subs of 10 s) for a solid image of the M49. A quick look takes 17 min; a showpiece 4 h 37 min. Under a Bortle 3 rural sky the solid figure drops to 28 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 23% 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 | 6 min37 subs | 24 min146 subs | 1 h 37 min584 subs |
| Bortle 2Typical dark site | 6 min39 subs | 26 min155 subs | 1 h 43 min617 subs |
| Bortle 3Rural | 7 min43 subs | 28 min170 subs | 1 h 53 min679 subs |
| Bortle 4Rural / suburban transition | 9 min52 subs | 35 min208 subs | 2 h 18 min831 subs |
| Bortle 5Suburban | 11 min67 subs | 45 min268 subs | 2 h 58 min1,071 subs |
| Bortle 6Bright suburban | 17 min104 subs | 1 h 09 min416 subs | 4 h 37 min1,661 subs |
| Bortle 7Suburban / urban transition | 29 min174 subs | 1 h 56 min696 subs | 7 h 44 min2,784 subs |
| Bortle 8City | 47 min283 subs | 3 h 09 min1,132 subs | 13 h4,528 subs |
| Bortle 9Inner city | 1 h 26 min516 subs | 5 h 44 min2,062 subs | 23 h8,248 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 30 min of run time. The Seestar S50’s battery (rated about 6 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 power bank 20000mAh 5V 3AThe S50 draws 5 V 3 A over USB-C and runs while charging; no PD needed.
- Seestar S50 dew shieldThe built-in heater copes with most nights; a shield helps in heavy dew and blocks stray light.
- red LED head torchRed light keeps your night vision; white light costs you twenty minutes of dark adaptation every time.
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Everything that fits the Seestar S50 →
How it frames
The M49 is 10′ × 8′ across. The Seestar S50 frames 1.28° × 0.72° at 2.39″ per pixel, so it fills 23% of the frame’s short side.
Longer subs
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode (app 2.5 and later). Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 28 min170 subs | 45 min268 subs | 1 h 56 min696 subs |
| 20 s | 24 min74 subs | 41 min123 subs | 1 h 52 min337 subs |
| 30 s | 23 min47 subs | 40 min80 subs | 1 h 51 min222 subs |
| 60 s | 30 min30 subs | 38 min39 subs | 1 h 50 min110 subs |
Leave the dual-band filter out for the M49. It is a galaxy, and it shines right across the spectrum. A dual-band filter keeps two emission lines and throws the rest away, so most of the light you came for is being stopped along with the sky. From a Bortle 6 sky it would be roughly 12 times slower.
About the M49
The brightest galaxy in the Virgo cluster, a featureless elliptical. Comes quickly but shows no structure.
NGC 4472 · Galaxy in Virgo · magnitude 8.4 · 10′ × 8′ · 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 ZWO Seestar S50
The scope that made smart astrophotography mainstream. 50 mm triplet, 2 MP sensor, dual-band filter on a wheel. Alt-Az stacking at 10 s, EQ mode unlocks 60 s. Out of production since 2026 and replaced by the S50 Pro, but there are a great many in use.
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode (app 2.5 and later). Built-in dual-band light-pollution filter, switchable in the app.
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 60 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 M49 from a Seestar S50? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M49 with the ZWO Seestar S50 Pro: 1 h 16 min from Bortle 6
- M49 with the ZWO Seestar S30: 1 h 13 min from Bortle 6
- M49 with the ZWO Seestar S30 Pro: 1 h 20 min from Bortle 6
- M49 with the DwarfLab DWARF 3: 1 h 41 min from Bortle 6
- M49 with the DwarfLab DWARF mini: 1 h 09 min from Bortle 6
- M49 with the DwarfLab Draco: 57 min from Bortle 6
- M49 with the DwarfLab DWARF II: 3 h 55 min from Bortle 6
- M49 with the Vaonis Vespera II: 1 h 09 min from Bortle 6
- M49 with the Vaonis Vespera Pro: 2 h 35 min from Bortle 6
- M49 with the Vaonis Vespera 3: 1 h 06 min from Bortle 6
- M49 with the Vaonis Vespera Pro 2: 2 h 27 min from Bortle 6
- M49 with the Unistellar eQuinox 2: 1 h 02 min from Bortle 6
- M49 with the Unistellar Odyssey: 4 h 46 min from Bortle 6
- M49 with the Celestron Origin: 18 min from Bortle 6
- M49 with the Celestron Origin Mark II: 25 min from Bortle 6
All telescopes for the M49 · All targets for the Seestar S50