How long to image the M107 with the ZWO Seestar S30 Pro
From a Bortle 6 suburban sky, the ZWO Seestar S30 Pro needs about 1 h 09 min (412 subs of 10 s) for a solid image of the M107. A quick look takes 17 min; a showpiece 4 h 35 min. Under a Bortle 3 rural sky the solid figure drops to 29 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 10% 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 | 25 min148 subs | 1 h 38 min591 subs |
| Bortle 2Typical dark site | 6 min39 subs | 26 min156 subs | 1 h 44 min624 subs |
| Bortle 3Rural | 7 min43 subs | 29 min172 subs | 1 h 54 min685 subs |
| Bortle 4Rural / suburban transition | 9 min53 subs | 35 min209 subs | 2 h 19 min834 subs |
| Bortle 5Suburban | 11 min67 subs | 45 min268 subs | 2 h 58 min1,070 subs |
| Bortle 6Bright suburban | 17 min103 subs | 1 h 09 min412 subs | 4 h 35 min1,648 subs |
| Bortle 7Suburban / urban transition | 29 min172 subs | 1 h 55 min688 subs | 7 h 38 min2,750 subs |
| Bortle 8City | 46 min279 subs | 3 h 06 min1,116 subs | 12 h4,461 subs |
| Bortle 9Inner city | 1 h 24 min507 subs | 5 h 38 min2,028 subs | 23 h8,111 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 M107 is 13′ across. The Seestar S30 Pro frames 3.99° × 2.24° at 3.74″ per pixel, so it fills 10% 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 | 29 min172 subs | 45 min268 subs | 1 h 55 min688 subs |
| 20 s | 24 min73 subs | 40 min121 subs | 1 h 50 min331 subs |
| 30 s | 23 min46 subs | 39 min78 subs | 1 h 49 min218 subs |
| 60 s | 30 min30 subs | 37 min38 subs | 1 h 47 min108 subs |
Leave the dual-band filter out for the M107. It is a globular cluster, 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 M107
A loose, dust-dimmed globular in Ophiuchus. Modest but straightforward.
NGC 6171 · Globular cluster in Ophiuchus · magnitude 7.9 · 13′ · best in May, Jun, Jul. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Globular clusters are point sources packed tight, so they come quickly: the core resolves into stars within a handful of minutes on any smart scope. More time deepens the halo and pulls in the faint outer members. Use short subs so the core does not saturate into a white blob, and no filter.
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 M107 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
- M107 with the ZWO Seestar S50: 59 min from Bortle 6
- M107 with the ZWO Seestar S50 Pro: 1 h 05 min from Bortle 6
- M107 with the ZWO Seestar S30: 1 h 02 min from Bortle 6
- M107 with the DwarfLab DWARF 3: 1 h 26 min from Bortle 6
- M107 with the DwarfLab DWARF mini: 59 min from Bortle 6
- M107 with the DwarfLab Draco: 49 min from Bortle 6
- M107 with the DwarfLab DWARF II: 3 h 22 min from Bortle 6
- M107 with the Vaonis Vespera II: 59 min from Bortle 6
- M107 with the Vaonis Vespera Pro: 2 h 12 min from Bortle 6
- M107 with the Vaonis Vespera 3: 57 min from Bortle 6
- M107 with the Vaonis Vespera Pro 2: 2 h 06 min from Bortle 6
- M107 with the Unistellar eQuinox 2: 53 min from Bortle 6
- M107 with the Unistellar Odyssey: 4 h 05 min from Bortle 6
- M107 with the Celestron Origin: 16 min from Bortle 6
- M107 with the Celestron Origin Mark II: 22 min from Bortle 6
All telescopes for the M107 · All targets for the Seestar S30 Pro