How long to image the Carina Nebula with the ZWO Seestar S50 Pro
From a Bortle 6 suburban sky, the ZWO Seestar S50 Pro needs about 10 min (62 subs of 10 s with the built-in dual-band (LP filter) filter) for a solid image of the Carina Nebula. A quick look takes 3 min; a showpiece 41 min. Under a Bortle 3 rural sky the solid figure drops to 8 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it is just over the frame at 1.4×.
| Sky | Quick lookTarget obvious, still noisy | SolidClean enough to share | ShowpieceSmooth faint detail, print-worthy |
|---|---|---|---|
| Bortle 1Excellent dark site | 2 min12 subs | 8 min48 subs | 32 min191 subs |
| Bortle 2Typical dark site | 2 min13 subs | 8 min49 subs | 32 min193 subs |
| Bortle 3Rural | 2 min13 subs | 8 min49 subs | 33 min196 subs |
| Bortle 4Rural / suburban transition | 2 min13 subs | 8 min51 subs | 34 min204 subs |
| Bortle 5Suburban | 2 min14 subs | 9 min54 subs | 36 min216 subs |
| Bortle 6Bright suburban | 3 min16 subs | 10 min62 subs | 41 min247 subs |
| Bortle 7Suburban / urban transition | 3 min20 subs | 13 min77 subs | 51 min305 subs |
| Bortle 8City | 4 min25 subs | 16 min99 subs | 1 h 06 min395 subs |
| Bortle 9Inner city | 6 min37 subs | 24 min147 subs | 1 h 38 min588 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 13 min of run time. The Seestar S50 Pro’s battery (rated about 9 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 PD power bank 20000mAh 30WAccepts 12 V 3 A PD, so a 30 W bank tops up the 10,000 mAh cell while imaging.
- Seestar S50 Pro dew shieldDew heater is built in; a shield adds margin on damp nights. Check the listing says S50 Pro.
- 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 S50 Pro →
How it frames
The Carina Nebula is 120′ across. The Seestar S50 Pro frames 2.45° × 1.38° at 2.30″ per pixel, so it is just over the frame at 1.4×. Point at the part you want; the edges will fall outside the frame.
Longer subs
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode, and 60 s is the ceiling. Time for a solid image by sub length:
| Sub length | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| 10 s | 8 min49 subs | 9 min54 subs | 13 min77 subs |
| 20 s | 10 min30 subs | 10 min30 subs | 11 min34 subs |
| 30 s | 15 min30 subs | 15 min30 subs | 15 min30 subs |
| 60 s | 30 min30 subs | 30 min30 subs | 30 min30 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| UV/IR-cut (no light-pollution filter) | 6 min39 subs | 9 min56 subs | 21 min128 subs |
| dual-band (LP filter) | 8 min49 subs | 9 min54 subs | 13 min77 subs |
About the Carina Nebula
Four times the size and brightness of the Orion Nebula, the best emission nebula in the sky. Southern hemisphere only, and easy from anywhere it rises.
NGC 3372, Caldwell 92, Eta Carinae Nebula · Emission nebula in Carina · magnitude 1.0 · 120′ · best in Feb, Mar, Apr. Low or below the horizon from northern Europe; best from the southern US southwards.
Emission nebulae glow in a few narrow lines, mostly hydrogen-alpha (deep red) and doubly ionised oxygen (teal). A dual-band filter passes those lines and blocks most skyglow, which is why it cuts the time needed from a suburban sky so dramatically. Use it. From a genuinely dark site the gain is smaller because there is less skyglow to block, and read noise becomes the limit, which is where longer subs (EQ mode, or Expert Mode on a Vespera) earn their keep.
Stars lose colour through a dual-band filter; a short broadband stack blended in fixes that if you care.
About the ZWO Seestar S50 Pro
The S50 optics at 260 mm on an 8 MP 1/1.2-inch sensor: a wider, taller field, four times the pixels, and 60 s subs in EQ mode. Per pixel it is a whisker slower than the S50 because of the longer focal length; the long subs make it the better dark-site scope.
10, 20 and 30 s in Alt-Az; 60 s only in EQ mode, and 60 s is the ceiling. 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 Carina Nebula from a Seestar S50 Pro? Email it with your total time and sky to [email protected] and it goes here, credited.
Same target, other telescopes
- Carina Nebula with the ZWO Seestar S50: 9 min from Bortle 6
- Carina Nebula with the ZWO Seestar S30: 10 min from Bortle 6
- Carina Nebula with the ZWO Seestar S30 Pro: 11 min from Bortle 6
- Carina Nebula with the DwarfLab DWARF 3: 12 min from Bortle 6
- Carina Nebula with the DwarfLab DWARF mini: 9 min from Bortle 6
- Carina Nebula with the DwarfLab Draco: 15 min from Bortle 6
- Carina Nebula with the DwarfLab DWARF II: 41 min from Bortle 6
- Carina Nebula with the Vaonis Vespera II: 12 min from Bortle 6
- Carina Nebula with the Vaonis Vespera Pro: 27 min from Bortle 6
- Carina Nebula with the Vaonis Vespera 3: 12 min from Bortle 6
- Carina Nebula with the Vaonis Vespera Pro 2: 26 min from Bortle 6
- Carina Nebula with the Unistellar eQuinox 2: 11 min from Bortle 6
- Carina Nebula with the Unistellar Odyssey: 48 min from Bortle 6
- Carina Nebula with the Celestron Origin: 5 min from Bortle 6
- Carina Nebula with the Celestron Origin Mark II: 5 min from Bortle 6
All telescopes for the Carina Nebula · All targets for the Seestar S50 Pro