How long to image the M110 with the ZWO Seestar S30
From a Bortle 6 suburban sky, the ZWO Seestar S30 needs about 3 h 58 min (1,430 subs of 10 s) for a solid image of the M110. A quick look takes 1 h; a showpiece 16 h. Under a Bortle 3 rural sky the solid figure drops to 1 h 35 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 31% 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 | 20 min121 subs | 1 h 21 min484 subs | 5 h 23 min1,936 subs |
| Bortle 2Typical dark site | 21 min129 subs | 1 h 25 min513 subs | 5 h 42 min2,052 subs |
| Bortle 3Rural | 24 min142 subs | 1 h 35 min568 subs | 6 h 19 min2,272 subs |
| Bortle 4Rural / suburban transition | 29 min176 subs | 1 h 57 min701 subs | 7 h 47 min2,804 subs |
| Bortle 5Suburban | 38 min228 subs | 2 h 32 min912 subs | 10 h3,648 subs |
| Bortle 6Bright suburban | 1 h358 subs | 3 h 58 min1,430 subs | 16 h5,717 subs |
| Bortle 7Suburban / urban transition | 1 h 41 min604 subs | 6 h 43 min2,416 subs | 27 h9,661 subs |
| Bortle 8City | 2 h 44 min987 subs | 11 h3,946 subs | 44 h15,784 subs |
| Bortle 9Inner city | 5 h1,803 subs | 20 h7,211 subs | 80 h28,842 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 5 h 10 min of run time. The Seestar S30’s battery is rated at about 6 h, which is cutting it fine; take a power bank. (Bortle 6, solid image; we allow 30% over the integration time.)
- USB-C power bank 10000mAh 5V 3A6,000 mAh inside; a 10,000 mAh 5 V 3 A bank roughly doubles a session.
- Seestar S30 dew shieldHeater is built in; a cheap shield reduces dew and stray light.
- 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 →
How it frames
The M110 is 22′ × 11′ across. The Seestar S30 frames 2.13° × 1.20° at 3.99″ per pixel, so it fills 31% 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 | 1 h 35 min568 subs | 2 h 32 min912 subs | 6 h 43 min2,416 subs |
| 20 s | 1 h 15 min226 subs | 2 h 13 min398 subs | 6 h 23 min1,150 subs |
| 30 s | 1 h 09 min138 subs | 2 h 06 min253 subs | 6 h 17 min754 subs |
| 60 s | 1 h 02 min63 subs | 2 h120 subs | 6 h 10 min371 subs |
Leave the dual-band filter out for the M110. 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 14 times slower.
About the M110
Andromeda's larger, diffuse elliptical companion. Low surface brightness; it fades into the background in short stacks.
NGC 205 · Galaxy in Andromeda · magnitude 8.1 · 22′ × 11′ · best in Sep, Oct, Nov. 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
Wider and lighter than the S50 with the same 2.9 µm pixels, so its per-pixel speed on extended targets is close despite the smaller aperture. Ideal for big nebulae.
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.
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 M110 from a Seestar S30? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- M110 with the ZWO Seestar S50: 3 h 46 min from Bortle 6
- M110 with the ZWO Seestar S50 Pro: 4 h 08 min from Bortle 6
- M110 with the ZWO Seestar S30 Pro: 4 h 23 min from Bortle 6
- M110 with the DwarfLab DWARF 3: 5 h 28 min from Bortle 6
- M110 with the DwarfLab DWARF mini: 3 h 45 min from Bortle 6
- M110 with the DwarfLab Draco: 3 h 06 min from Bortle 6
- M110 with the DwarfLab DWARF II: 13 h from Bortle 6
- M110 with the Vaonis Vespera II: 3 h 46 min from Bortle 6
- M110 with the Vaonis Vespera Pro: 8 h 28 min from Bortle 6
- M110 with the Vaonis Vespera 3: 3 h 36 min from Bortle 6
- M110 with the Vaonis Vespera Pro 2: 8 h 04 min from Bortle 6
- M110 with the Unistellar eQuinox 2: 3 h 28 min from Bortle 6
- M110 with the Unistellar Odyssey: 16 h from Bortle 6
- M110 with the Celestron Origin: 1 h from Bortle 6
- M110 with the Celestron Origin Mark II: 1 h 22 min from Bortle 6
All telescopes for the M110 · All targets for the Seestar S30