ZWO Seestar S30: how long to image deep-sky targets
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.
| Spec | Value |
|---|---|
| Aperture | 30 mm |
| Focal length | 150 mm (f/5.0) |
| Sensor | Sony IMX662, 1920 × 1080, 2.9 µm pixels |
| Pixel scale | 3.99″ per pixel |
| Field of view | 2.13° × 1.20° (128′ × 72′) |
| Sub exposures | 10 s, 20 s, 30 s (default 10 s) |
| Filter | Built-in dual-band filter. |
| Read noise used | 1 e⁻ |
Popular targets
| Target | Bortle 4 | Bortle 6 | Bortle 8 |
|---|---|---|---|
| Andromeda GalaxyGalaxy | 42 min254 subs | 1 h 27 min525 subs | 4 h 04 min1,465 subs |
| Orion NebulaEmission nebula, dual-band | 10 min61 subs | 12 min75 subs | 21 min125 subs |
| PleiadesReflection nebula | 1 h 16 min456 subs | 2 h 42 min971 subs | 7 h 38 min2,751 subs |
| Whirlpool GalaxyGalaxy | 29 min177 subs | 59 min352 subs | 2 h 39 min955 subs |
| Bode's GalaxyGalaxy | 31 min188 subs | 1 h 04 min383 subs | 2 h 56 min1,056 subs |
| Pinwheel GalaxyGalaxy | 2 h 08 min766 subs | 4 h 37 min1,661 subs | 13 h4,754 subs |
| Hercules ClusterGlobular cluster | 5 min30 subs | 7 min44 subs | 18 min107 subs |
| Dumbbell NebulaPlanetary nebula, dual-band | 16 min99 subs | 20 min121 subs | 33 min198 subs |
| Ring NebulaPlanetary nebula, dual-band | 6 min37 subs | 7 min42 subs | 10 min60 subs |
| Lagoon NebulaEmission nebula, dual-band | 16 min94 subs | 20 min119 subs | 34 min205 subs |
| Eagle NebulaEmission nebula, dual-band | 46 min275 subs | 1 h 01 min366 subs | 1 h 53 min680 subs |
| Omega NebulaEmission nebula, dual-band | 13 min81 subs | 17 min102 subs | 29 min173 subs |
| Trifid NebulaEmission nebula, dual-band | 33 min200 subs | 44 min263 subs | 1 h 20 min480 subs |
| Triangulum GalaxyGalaxy | 1 h 16 min456 subs | 2 h 42 min971 subs | 7 h 38 min2,751 subs |
| North America NebulaEmission nebula, dual-band | 1 h 03 min381 subs | 1 h 25 min512 subs | 2 h 41 min965 subs |
| Western Veil NebulaSupernova remnant, dual-band | 1 h 09 min414 subs | 1 h 33 min557 subs | 2 h 56 min1,054 subs |
| Eastern Veil NebulaSupernova remnant, dual-band | 58 min351 subs | 1 h 18 min471 subs | 2 h 27 min884 subs |
| Elephant's Trunk NebulaEmission nebula, dual-band | 1 h 44 min627 subs | 2 h 22 min855 subs | 4 h 34 min1,642 subs |
| Iris NebulaReflection nebula | 54 min325 subs | 1 h 53 min681 subs | 5 h 19 min1,913 subs |
| Pacman NebulaEmission nebula, dual-band | 1 h 15 min449 subs | 1 h 41 min607 subs | 3 h 12 min1,152 subs |
| Heart NebulaEmission nebula, dual-band | 2 h 04 min742 subs | 2 h 49 min1,016 subs | 5 h 27 min1,963 subs |
| Rosette NebulaEmission nebula, dual-band | 1 h 03 min381 subs | 1 h 25 min512 subs | 2 h 41 min965 subs |
| Horsehead NebulaEmission nebula, dual-band | 1 h 28 min530 subs | 1 h 60 min720 subs | 3 h 49 min1,375 subs |
| Flame NebulaEmission nebula, dual-band | 24 min147 subs | 32 min190 subs | 57 min340 subs |
| California NebulaEmission nebula, dual-band | 1 h 28 min530 subs | 1 h 60 min720 subs | 3 h 49 min1,375 subs |
| Helix NebulaPlanetary nebula, dual-band | 1 h 28 min530 subs | 1 h 60 min720 subs | 3 h 49 min1,375 subs |
| Double ClusterOpen cluster | 5 min30 subs | 5 min30 subs | 6 min34 subs |
| NGC 891Galaxy | 1 h 17 min465 subs | 2 h 44 min986 subs | 7 h 44 min2,787 subs |
| Sombrero GalaxyGalaxy | 24 min146 subs | 47 min283 subs | 2 h 05 min753 subs |
| Sunflower GalaxyGalaxy | 48 min287 subs | 1 h 39 min593 subs | 4 h 35 min1,651 subs |
All 170 targets have a page for the Seestar S30.
Getting the most from the Seestar S30
20 s and 30 s subs need EQ mode. Built-in dual-band 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.
Useful gear
Power, dew control and a stable tripod are what stop a long session early. Search links, not specific endorsements; check fit for your model.