I imaged the Iris Nebula for 3 nights from my backyard, sans filter, and combined the best 16 hours of 5 min subs.
I've worked to improve my processing compared to prior attempts (in APP and PS).
Version 5 (current): Here, I've reexamined my APP processing, realizing that for heavily blue scenes like this one, it auto-saturation overstretches the reds. I also made modest use of APP's built-in sharpening, and exported a broader stretch to get the molecular cloud details.
In APP: - Regular light pollution processing in APP at 30% stretch
- Reduce star size by 10%, reduce intensity by 20%
- Black body star calibration
- Set sharpening at 0.5%. Increase the HL value to 20 to deal with the bright central star
- Save at 30% stretch, 2 sigma, 0 base
In PS: - NoiseXTerminator (60% denoise 80% sharpen)
- Topaz (low light profile, 1% reduce noise, 0% sharpen, 50% recover original detail)
- Unsharp mask (75%, 1.5 pixels)
- Auto-contrast
- Curves (linear)
- Adjust Hue/Saturation:
- Red: -10 saturation, +5 lightness to tone down the brown molecular clouds
- Yellow: -5 saturation, +5 lightness
- Cyan: +20 saturation, -10 lightness to ehlp emphasize the iris
- Blue: +15 saturation, -5 lightness to further emphasize the Iris
- Magenta: +15 saturation, -5 lightness to preserve the purples in the Iris (little effect)
- Color balance (mids): magenta/green: -15 (the scene was a little green-blueish)
*****
Version 1:
In APP: - Regular light pollution processing in APP at 30% stretch
- Reduce star size and intensity by 10%
- Save at 20% stretch, 3 signa, 0 background
In PS: - NoiseXTerminator (60% denoise 60% sharpen)
- Topaz (Low light profile, 1% denoise, 0% sharpen)
- Unsharp mask (150%, 1.5 pixels)
- Auto-levels (use their black level, reset gamma to 1)
- Curves (use a custom "molecular clouds" profile that I'll show in a moment)
- Auto-contrast (not much effect)
- Curves (use a custom "comet" profile that I'll show in a moment)
- Auto-levels (use their black point and a 1.1 gamma)
- Adjust Hue/Saturation:
- Red: -10 saturation, +10 lightness to tone down the brown molecular clouds
- Blue: +20 saturation, -10 lightness to further emphasize the Iris
- Magenta: +10 saturation, -5 lightness to preserve the purples in the Iris
Version 2: Here, I've tried to simplify the processing and make sharpening a little less "crispy" and reduce artifacts.
In APP: - Regular light pollution processing in APP at 30% stretch
- Reduce star size and intensity by 10%
- Save at 20% stretch, 3 sigma, 0 background
In PS: - NoiseXTerminator (60% denoise 80% sharpen)
- Unsharp mask (50%, 1.5 pixels)
- Auto-levels (use their black level, reset gamma to 1)
- Curves (use a newer custom "molecular clouds 2023" profile that I'll show in a moment)
- Adjust Hue/Saturation:
- Red: -10 saturation, +50 lightness to tone down the brown molecular clouds
- Blue: +10 saturation, +0 lightness to further emphasize the Iris
- Magenta: +5 saturation, +0 lightness to preserve the purples in the Iris
Version 3: Here, I've tried to simplify the processing and make sharpening a little less "crispy" and reduce artifacts.
In APP: - Regular light pollution processing in APP at 30% stretch
- Reduce star size and intensity by 10%
- Save at 20% stretch, 3 sigma, 0 background
In PS: - NoiseXTerminator (60% denoise 80% sharpen)
- Topaz (low light profile, 1% reduce noise, 0% sharpen, 50% recover original detail)
- Unsharp mask (50%, 1.5 pixels)
- Auto-levels (use their black level, reset gamma to 1)
- Auto-contrast
- Curves (use a newer custom "molecular clouds 2023" profile that I'll show in a moment)
- Curves (use a newer custom "molecular clouds" profile that I'll show in a moment)
- Adjust Hue/Saturation:
- Red: -10 saturation, +5 lightness to tone down the brown molecular clouds
- Yellow: +0 saturation, +5 lightness
- Cyan: +10 saturation, +0 lightness
- Blue: +10 saturation, +0 lightness to further emphasize the Iris
- Magenta: +5 saturation, +5 lightness to preserve the purples in the Iris
Version 4: Minor variation on V3
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