How long to image the Flame Nebula with the ZWO Seestar S50 Pro
From a Bortle 6 suburban sky, the ZWO Seestar S50 Pro needs about 35 min (213 subs of 10 s with the built-in dual-band (LP filter) filter) for a solid image of the Flame Nebula. A quick look takes 9 min; a showpiece 2 h 21 min. Under a Bortle 3 rural sky the solid figure drops to 26 min. At Bortle 6 the limit is a mix of skyglow and read noise. In this scope's field it fills 36% 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 | 6 min38 subs | 25 min152 subs | 1 h 41 min605 subs |
| Bortle 2Typical dark site | 6 min39 subs | 25 min153 subs | 1 h 42 min612 subs |
| Bortle 3Rural | 7 min40 subs | 26 min157 subs | 1 h 44 min627 subs |
| Bortle 4Rural / suburban transition | 7 min42 subs | 28 min166 subs | 1 h 50 min661 subs |
| Bortle 5Suburban | 7 min45 subs | 30 min179 subs | 1 h 59 min715 subs |
| Bortle 6Bright suburban | 9 min54 subs | 35 min213 subs | 2 h 21 min849 subs |
| Bortle 7Suburban / urban transition | 11 min69 subs | 46 min276 subs | 3 h 04 min1,103 subs |
| Bortle 8City | 16 min94 subs | 1 h 02 min375 subs | 4 h 10 min1,498 subs |
| Bortle 9Inner city | 24 min147 subs | 1 h 37 min585 subs | 6 h 30 min2,340 subs |
Power and kit for this session
Allowing for slewing, focusing and rejected subs, that is about 46 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, and 30% off the battery for a December night.)
- 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.
- hand warmers long lastingAir-activated packs give hours of heat for the person; winter nights are long and you spend most of them standing still.
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Everything that fits the Seestar S50 Pro →
How it frames
The Flame Nebula is 30′ across. The Seestar S50 Pro frames 2.45° × 1.38° at 2.30″ per pixel, so it fills 36% of the frame’s short side.
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 | 26 min157 subs | 30 min179 subs | 46 min276 subs |
| 20 s | 20 min60 subs | 24 min71 subs | 40 min120 subs |
| 30 s | 18 min36 subs | 21 min43 subs | 38 min76 subs |
| 60 s | 30 min30 subs | 30 min30 subs | 36 min36 subs |
With and without the dual-band filter
| Filter | Bortle 3 | Bortle 5 | Bortle 7 |
|---|---|---|---|
| UV/IR-cut (no light-pollution filter) | 21 min129 subs | 33 min201 subs | 1 h 26 min518 subs |
| dual-band (LP filter) | 26 min157 subs | 30 min179 subs | 46 min276 subs |
About the Flame Nebula
A bright emission nebula beside Alnitak, split by a dark lane like a tree. Alnitak's glare is the main problem; keep it out of the frame if you can.
NGC 2024 · Emission nebula in Orion · magnitude 10.0 · 30′ · best in Nov, Dec, Jan. Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
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 Flame 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
- Flame Nebula with the ZWO Seestar S50: 32 min from Bortle 6
- Flame Nebula with the ZWO Seestar S30: 36 min from Bortle 6
- Flame Nebula with the ZWO Seestar S30 Pro: 38 min from Bortle 6
- Flame Nebula with the DwarfLab DWARF 3: 40 min from Bortle 6
- Flame Nebula with the DwarfLab DWARF mini: 31 min from Bortle 6
- Flame Nebula with the DwarfLab Draco: 25 min from Bortle 6
- Flame Nebula with the DwarfLab DWARF II: 2 h 41 min from Bortle 6
- Flame Nebula with the Vaonis Vespera II: 47 min from Bortle 6
- Flame Nebula with the Vaonis Vespera Pro: 1 h 46 min from Bortle 6
- Flame Nebula with the Vaonis Vespera 3: 45 min from Bortle 6
- Flame Nebula with the Vaonis Vespera Pro 2: 1 h 41 min from Bortle 6
- Flame Nebula with the Unistellar eQuinox 2: 42 min from Bortle 6
- Flame Nebula with the Unistellar Odyssey: 3 h 15 min from Bortle 6
- Flame Nebula with the Celestron Origin: 13 min from Bortle 6
- Flame Nebula with the Celestron Origin Mark II: 17 min from Bortle 6
All telescopes for the Flame Nebula · All targets for the Seestar S50 Pro