Processing story / East Veil Nebula NGC 6992
Revealing the East Veil filaments
Two narrowband channels, 29 hours and 10 minutes of exposure, and a careful separation of nebula and stars. Follow the choices behind this red and cyan HOO image.
Photography and processing by Michael Page
- HOO exposure
- 29 h 10 min
- Light frames
- 350
- Per exposure
- 300 s
- From capture to stars
- 6 stages
Preserve the filaments and balance the stars
The aim was to preserve the fine filaments while keeping the dense star field from taking over. Hα supplied red and O III supplied green and blue. Background neutralization made a shared stretch practical, and separating the stars allowed a small contrast and saturation lift on the nebula before restoring a gently reduced star field.
Processing the starless nebula and extracted stars separately made the finishing adjustments easier to judge without changing both at once.
See the difference
Compare the saved stages
A gentle finish on the nebula
Compare the saved starless image before and after contrast and saturation adjustments.
Drag the arrows on the image to compare. You can also use the arrow keys when the handle is selected.
Saved versions with the same framing and display conversion. This comparison includes both contrast and saturation changes; it does not isolate one setting.
Restore the reduced stars
Compare the finished starless nebula with the accepted recombination.
Drag the arrows on the image to compare. You can also use the arrow keys when the handle is selected.
The final image adds the retained reduced stars at full blend opacity. No additional stretch or brightness matching is applied to these web exports.
At the telescope
- Telescope
- William Optics UltraCat 108
- Camera
- ZWO ASI2600MM
- Hα filter
- Antlia Narrowband Hα 4.5 nm
- O III filter
- Antlia Narrowband O III 3 nm
- Camera settings
- Gain 100 · Offset 50 · −5 °C
- Processing
- PixInsight · HOO
| Channel | Frames | Exposure |
|---|---|---|
| Hα | 175 | 14 h 35 min |
| O III | 175 | 14 h 35 min |
Both channels contribute 14 h 35 min to the final HOO image. Hα maps to red; O III maps to both green and blue. These are mapped narrowband colors, including the stars.
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