HDR: High Dynamic Range: Architecture

I am in the middle of my first HDR (High Dynamic Range) project at the Casa Cassara Winery & Vineyard Estate ranch-house located just to the west of Buellton, California, north of the Santa Ynez River and Santa Rosa Road and south of Hwy 246 that runs to Lompoc. I expect that anyone who reads this blog is familiar, at least in concept, with HDR. Quickly, it is a technique in which several (generally three to nine) exposure variations are taken of the same frame and then combined into a pseudo image with a huge dynamic range, as much as 18 stops of luminance. This requires special software as the numeric values required to represent this range exceed the standard fixed point arithmetic of most image editing software. In my case, I am using Photomatix Pro 3.2.1 that assembles the base HDR image using floating point numbers.

What is the goal of all this extra effort and fancy software? To produce an image that has detail in both the very dark and very light portions of a photograph. I find this most easily conceived by thinking of taking a photograph in a room with the lights on but no flash. Under normal circumstances this would result in an image with localized pools of light around the light fixtures and very dark elsewhere and perhaps with pretty harsh shadows along with burned out areas very close to the lights themselves. With HDR, both the dark and light areas are generally preserved and have good detail.

I'm not going into much of any detail with this blog entry beyond posting a couple of images taken at the estate using a Canon 1Ds Mark III 21MP body, Canon 14mm f/2.8L lens on a Gitzo tripod with Really Right Stuff ball head and Canon shutter release. The exposures were ISO 100, Av priority, evaluative metering, five brackets 1-1/3 stops apart and mirror lockup for all images.

The first image was shot just as the sun was about to set behind the far ridge. The sky is actually very smokey as a result of the ongoing Le Brea Fire in northern Santa Barbara County. The direction where the sun is setting is toward Lompoc and the Pacific Ocean, about 20 miles distant. To the right of the house is the estate Pinot Noir vineyard, currently netted to protect the grapes from birds. Click on the image to see a larger version stored at blogspot.com.

The second image is the entryway to the house, showing detail in the bricks, the statue in the fountain, nice lighting on the windows and a pretty sky.

The final image of the Great Room shows detail in the wood of the vaulted ceiling, near the lighting fixtures and outside the windows, which is very blue due to the color dominance of the incandescent lighting inside.

In the next installment on this project I will show some comparison images using the "as metered" frames compared to the HDR assemblies.

In the meantime, travel safe!

Dwight