How long to image the M60 with the ZWO Seestar S30 Pro
From a Bortle 6 suburban sky, the ZWO Seestar S30 Pro needs about 1 h 08 min (411 subs of 10 s) for a solid image of the M60. A quick look takes 17 min; a showpiece 4 h 34 min. Under a Bortle 3 rural sky the solid figure drops to 30 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 5% 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 | 7 min40 subs | 26 min159 subs | 1 h 46 min634 subs |
| Bortle 2Typical dark site | 7 min42 subs | 28 min167 subs | 1 h 51 min665 subs |
| Bortle 3Rural | 8 min46 subs | 30 min181 subs | 2 h723 subs |
| Bortle 4Rural / suburban transition | 9 min55 subs | 36 min217 subs | 2 h 24 min865 subs |
| Bortle 5Suburban | 11 min69 subs | 45 min273 subs | 3 h 02 min1,090 subs |
| Bortle 6Bright suburban | 17 min103 subs | 1 h 08 min411 subs | 4 h 34 min1,642 subs |
| Bortle 7Suburban / urban transition | 28 min169 subs | 1 h 52 min674 subs | 7 h 29 min2,694 subs |
| Bortle 8City | 45 min271 subs | 3 h1,082 subs | 12 h4,326 subs |
| Bortle 9Inner city | 1 h 21 min488 subs | 5 h 25 min1,952 subs | 22 h7,808 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 1 h 29 min of run time. The Seestar S30 Pro’s battery (rated about 5 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 10000mAh 5V 3A5 V 3 A input and it runs while charging.
- Seestar S30 Pro dew shieldActive anti-dew is built in; a shield adds margin. The S30 Pro front differs from the S30, so check the listing.
- 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 Seestar S30 Pro →
How it frames
The M60 is 7′ × 6′ across. The Seestar S30 Pro frames 3.99° × 2.24° at 3.74″ per pixel, so it fills 5% of the frame’s short side.
Longer subs
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode, which needs the TH10 head. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 30 min181 subs | 45 min273 subs | 1 h 52 min674 subs |
| 20 s | 26 min79 subs | 41 min124 subs | 1 h 48 min325 subs |
| 30 s | 25 min50 subs | 40 min80 subs | 1 h 47 min214 subs |
| 60 s | 30 min30 subs | 39 min39 subs | 1 h 45 min106 subs |
Leave the dual-band filter out for the M60. 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 M60
A giant elliptical with the spiral NGC 4647 touching it. A neat pair in one frame.
NGC 4649 · Galaxy in Virgo · magnitude 8.8 · 7′ × 6′ · 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 S30 Pro
The S30 optics upgraded to a quadruplet in front of an 8 MP IMX585. Same speed per pixel as the S30, four times the pixels, so you can crop hard.
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode, which needs the TH10 head. Built-in UV/IR-cut, dual-band (OIII 30 nm / Hα 20 nm) and dark filters on the telephoto camera.
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 M60 from a Seestar S30 Pro? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M60 with the ZWO Seestar S50: 59 min from Bortle 6
- M60 with the ZWO Seestar S50 Pro: 1 h 05 min from Bortle 6
- M60 with the ZWO Seestar S30: 1 h 02 min from Bortle 6
- M60 with the DwarfLab DWARF 3: 1 h 26 min from Bortle 6
- M60 with the DwarfLab DWARF mini: 59 min from Bortle 6
- M60 with the DwarfLab Draco: 49 min from Bortle 6
- M60 with the DwarfLab DWARF II: 3 h 19 min from Bortle 6
- M60 with the Vaonis Vespera II: 59 min from Bortle 6
- M60 with the Vaonis Vespera Pro: 2 h 12 min from Bortle 6
- M60 with the Vaonis Vespera 3: 56 min from Bortle 6
- M60 with the Vaonis Vespera Pro 2: 2 h 06 min from Bortle 6
- M60 with the Unistellar eQuinox 2: 52 min from Bortle 6
- M60 with the Unistellar Odyssey: 4 h from Bortle 6
- M60 with the Celestron Origin: 16 min from Bortle 6
- M60 with the Celestron Origin Mark II: 22 min from Bortle 6
All telescopes for the M60 · All targets for the Seestar S30 Pro