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— HDRI Pictures: Nightshot 197 —
42.5% of original size. Photographed on 31. July 2008 at 22:45 CEST.
Number of photographs: 6, exposure times (shutter speeds): 1 second to 30 seconds,
f-stop: f/8,
equivalent sensitivity: 200 ASA; dynamic range: 2,285:1, radiosity: 3.
Assembled without auto alignment in Picturenaut 2.12 (1). The 30 second exposure was added 4 times to itself in HDRShop and saved as HDRI (2).
- 6 Exposures HDRI:
- PreGamma: 1.00
- Brightness: -2.00
- Saturation: 0.25
- Strength: 0.00
- Radius: 1.00
- Radiance: 0.00
- Halos: -1.00
- Highlights: 0.00
- Shadows: 0.00
- Midtones: 0.10
- 30 Second exposure added 4 x:
- PreGamma: 1.00
- Brightness: -8.00
- Saturation: 0.10
- Strength: 0.00
- Radius: 1.00
- Radiance: 1.00
- Halos: -1.00
- Highlights: 0.00
- Shadows: -0.10
- Midtones: 0.50
Both tone-mapped pictures were combined in PhotoImpact 4: 75% (1) and 25% (2). Lens used: Nikkor 10.5 mm Fisheye. The finished picture was de-fished in PTLens. Some corrective adjustments were made in Photoshop (saturation, graduation).
This is an experiment. Observations: without proper tracking the stars wander und there are finally more than actually are — but this was to be expected. In the centre of the sky, the light trace of an aeroplane is visible. Ther was a slight breeze which explains why the birch tree in the foreground is blurred.
With the noise reduction engaged the noise is rather low but visible nevertheless if the brightness of the original pictures is boosted up. There is absolutely no noise in the HDRI. If the brightness is excessively increased, the sky gets uniformly grey. For the 30 second exposure that was added four times and saved as HDRI, the noise also increased four fold. HDRI astro photos are the right way to get a grip on the noise every long exposure produces.
Left, 30 seconds exposure with brigtness increased excessively. Right, tone mapped HDRI with extremely increased brightness.
© 2004 - 2018 by Horo Wernli.