How long to image the NGC 6914 with the ZWO Seestar S30
From a Bortle 6 suburban sky, the ZWO Seestar S30 needs about 6 h 23 min (2,298 subs of 10 s) for a solid image of the NGC 6914. A quick look takes 1 h 36 min; a showpiece 26 h. Under a Bortle 3 rural sky the solid figure drops to 2 h 34 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 8% 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 | 33 min199 subs | 2 h 12 min794 subs | 8 h 49 min3,173 subs |
| Bortle 2Typical dark site | 35 min210 subs | 2 h 20 min840 subs | 9 h 20 min3,358 subs |
| Bortle 3Rural | 39 min232 subs | 2 h 34 min927 subs | 10 h3,707 subs |
| Bortle 4Rural / suburban transition | 47 min285 subs | 3 h 10 min1,139 subs | 13 h4,554 subs |
| Bortle 5Suburban | 1 h 01 min369 subs | 4 h 06 min1,474 subs | 16 h5,896 subs |
| Bortle 6Bright suburban | 1 h 36 min575 subs | 6 h 23 min2,298 subs | 26 h9,190 subs |
| Bortle 7Suburban / urban transition | 2 h 41 min967 subs | 11 h3,867 subs | 43 h15,465 subs |
| Bortle 8City | 4 h 23 min1,576 subs | 18 h6,303 subs | 70 h25,209 subs |
| Bortle 9Inner city | 7 h 59 min2,875 subs | 32 h11,498 subs | 130+ h45,989 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 8 h 18 min of run time. That is more than one night: over 2 nights, about 4 h 09 min each. The Seestar S30’s battery (rated about 6 h) should cover each night; 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 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.
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Everything that fits the Seestar S30 →
How it frames
The NGC 6914 is 6′ across. The Seestar S30 frames 2.13° × 1.20° at 3.99″ per pixel, so it fills 8% 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 | 2 h 34 min927 subs | 4 h 06 min1,474 subs | 11 h3,867 subs |
| 20 s | 2 h 04 min372 subs | 3 h 35 min645 subs | 10 h1,841 subs |
| 30 s | 1 h 53 min227 subs | 3 h 25 min410 subs | 10 h1,207 subs |
| 60 s | 1 h 43 min104 subs | 3 h 14 min195 subs | 9 h 53 min594 subs |
Leave the dual-band filter out for the NGC 6914. It is a reflection nebula, 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 NGC 6914
Blue reflection patches floating on a sea of red hydrogen in Cygnus. Broadband for the blue; dual-band would remove the point.
vdB 131/132 · Reflection nebula in Cygnus · magnitude 9.0 · 6′ · best in Jul, Aug, Sep. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Reflection nebulae are starlight scattered by dust, so they are broadband and blue. A dual-band filter removes almost all of it; do not use one. These are among the faintest structures a smart scope can attempt and the figures run long. A dark sky matters more here than for any other type, and the Moon must be down.
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 NGC 6914 from a Seestar S30? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- NGC 6914 with the ZWO Seestar S50: 6 h 04 min from Bortle 6
- NGC 6914 with the ZWO Seestar S50 Pro: 6 h 38 min from Bortle 6
- NGC 6914 with the ZWO Seestar S30 Pro: 7 h 02 min from Bortle 6
- NGC 6914 with the DwarfLab DWARF 3: 8 h 48 min from Bortle 6
- NGC 6914 with the DwarfLab DWARF mini: 6 h 02 min from Bortle 6
- NGC 6914 with the DwarfLab Draco: 4 h 59 min from Bortle 6
- NGC 6914 with the DwarfLab DWARF II: 21 h from Bortle 6
- NGC 6914 with the Vaonis Vespera II: 6 h 04 min from Bortle 6
- NGC 6914 with the Vaonis Vespera Pro: 14 h from Bortle 6
- NGC 6914 with the Vaonis Vespera 3: 5 h 48 min from Bortle 6
- NGC 6914 with the Vaonis Vespera Pro 2: 13 h from Bortle 6
- NGC 6914 with the Unistellar eQuinox 2: 5 h 33 min from Bortle 6
- NGC 6914 with the Unistellar Odyssey: 26 h from Bortle 6
- NGC 6914 with the Celestron Origin: 1 h 36 min from Bortle 6
- NGC 6914 with the Celestron Origin Mark II: 2 h 12 min from Bortle 6
All telescopes for the NGC 6914 · All targets for the Seestar S30