How long to image the Helix Nebula with the ZWO Seestar S30 Pro
From a Bortle 6 suburban sky, the ZWO Seestar S30 Pro needs about 2 h 25 min (872 subs of 10 s with the built-in dual-band (LP filter) filter) for a solid image of the Helix Nebula. A quick look takes 36 min; a showpiece 9 h 41 min. Under a Bortle 3 rural sky the solid figure drops to 1 h 43 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 19% 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 | 25 min148 subs | 1 h 39 min592 subs | 6 h 34 min2,365 subs |
| Bortle 2Typical dark site | 25 min150 subs | 1 h 40 min600 subs | 6 h 40 min2,399 subs |
| Bortle 3Rural | 26 min154 subs | 1 h 43 min616 subs | 6 h 51 min2,464 subs |
| Bortle 4Rural / suburban transition | 27 min164 subs | 1 h 49 min656 subs | 7 h 17 min2,622 subs |
| Bortle 5Suburban | 30 min180 subs | 2 h718 subs | 7 h 59 min2,872 subs |
| Bortle 6Bright suburban | 36 min218 subs | 2 h 25 min872 subs | 9 h 41 min3,485 subs |
| Bortle 7Suburban / urban transition | 48 min291 subs | 3 h 14 min1,163 subs | 13 h4,652 subs |
| Bortle 8City | 1 h 07 min405 subs | 4 h 29 min1,617 subs | 18 h6,466 subs |
| Bortle 9Inner city | 1 h 48 min646 subs | 7 h 11 min2,584 subs | 29 h10,333 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 3 h 09 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.
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How it frames
The Helix Nebula is 25′ × 22′ across. The Seestar S30 Pro frames 3.99° × 2.24° at 3.74″ per pixel, so it fills 19% 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 43 min616 subs | 2 h718 subs | 3 h 14 min1,163 subs |
| 20 s | 1 h 12 min218 subs | 1 h 29 min269 subs | 2 h 44 min491 subs |
| 30 s | 1 h 02 min125 subs | 1 h 19 min159 subs | 2 h 34 min308 subs |
| 60 s | 52 min53 subs | 1 h 09 min70 subs | 2 h 24 min144 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| UV/IR-cut (no light-pollution filter) | 1 h 25 min513 subs | 2 h 21 min846 subs | 6 h 23 min2,300 subs |
| dual-band (LP filter) | 1 h 43 min616 subs | 2 h718 subs | 3 h 14 min1,163 subs |
About the Helix Nebula
The nearest bright planetary nebula, half the Moon's width but spread thin. Low from the UK; dual-band and a couple of hours make the eye appear.
NGC 7293, Caldwell 63 · Planetary nebula in Aquarius · magnitude 7.3 · 25′ × 22′ · best in Aug, Sep, Oct. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
Planetary nebulae are small but intensely bright per pixel in OIII and H-alpha, so they respond very well to a dual-band filter and do not need much time for the main shell. The faint outer halos most of them have are a different proposition and need hours. Keep subs short if the central region saturates.
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 Helix Nebula 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
- Helix Nebula with the ZWO Seestar S50: 2 h from Bortle 6
- Helix Nebula with the ZWO Seestar S50 Pro: 2 h 15 min from Bortle 6
- Helix Nebula with the ZWO Seestar S30: 2 h 20 min from Bortle 6
- Helix Nebula with the DwarfLab DWARF 3: 2 h 28 min from Bortle 6
- Helix Nebula with the DwarfLab DWARF mini: 1 h 58 min from Bortle 6
- Helix Nebula with the DwarfLab Draco: 1 h 35 min from Bortle 6
- Helix Nebula with the DwarfLab DWARF II: 11 h from Bortle 6
- Helix Nebula with the Vaonis Vespera II: 3 h 13 min from Bortle 6
- Helix Nebula with the Vaonis Vespera Pro: 7 h 14 min from Bortle 6
- Helix Nebula with the Vaonis Vespera 3: 3 h 05 min from Bortle 6
- Helix Nebula with the Vaonis Vespera Pro 2: 6 h 53 min from Bortle 6
- Helix Nebula with the Unistellar eQuinox 2: 2 h 57 min from Bortle 6
- Helix Nebula with the Unistellar Odyssey: 14 h from Bortle 6
- Helix Nebula with the Celestron Origin: 51 min from Bortle 6
- Helix Nebula with the Celestron Origin Mark II: 1 h 10 min from Bortle 6
All telescopes for the Helix Nebula · All targets for the Seestar S30 Pro