Alpine Lake Dam (HDR)

Alpine Lake Dam. (Mt. Tamalpias, CA) Feb. 5, 2011. This high-dynamic range image was made up from eight groups of three vertical exposures at 21 mega-pixels each! Stitched together with PTGui v 9.0.1, then tone-mapped with Photomatix Pro v4.0.2, the final image has a total of 10,286 x 5143 pixels!

I've always loved the design of this particular dam located on the north-western slopes of Mt. Tamalpias. I wanted to photograph an extremely high resolution panorama from below the dam looking up in order to try and capture the sense of scale and due to the extremely dynamic range of light in the scene (shady forested slopes and bright, partly cloudy skies), this was a perfect candidate for an HDR sequence.

Each RAW image was first processed in Adobe Lightroom 3 x64 and exported as 16-bit uncompressed TIFF files prior to stitching.

Shot on a Canon 5D Mark II with an EF 24-105mm f/4L IS USM lens mounted on a tri-pod and attached to a "Really Right Stuff" PG-02 LLR Pano-Gimbal Head, here are the settings for each of the three exposures in each of the eight locations.

Mode: Manual
Aperture: f/5.6
ISO 400
Focal Length: 24mm

1. Nominal Exposure: 1/200 sec
2. Highlights Exposure: 1/800 sec
3. Shadows Exposure: 1/50 sec

Normally, I might have decreased the ISO to 100 or 50 and set the aperture at f/8 or f/11 for a more of a soft flowing, extremely low noise ribbon effect on the water, but in hindsight, I think I was actually trying to freeze the water on this one.