High Dynamic Range Masterclass: Page 4
What is HDR?
Dynamic range is defined as the ratio between the brightest and the darkest areas of a scene. Therefore, when referring to a ‘high’ dynamic range, we are concerned with displaying a wider range of bright and dark areas than is possible in standard digital photography, or a limited dynamic range image.
The process of the High Dynamic Range imaging technique manages to overcome the restrictions of the limited dynamic range of conventional digital cameras by utilising both exposure blending and tone-mapping techniques in tandem, using either recent versions of Photoshop CS or specialist software packages.
The idea is to take several images of the same subject at different exposures, either utilising AEB (automatic exposure bracketing) or manually, and then merge them together. While the results can be striking, there are potential problems in production, so it can take a lot of practice to perfect. The number of exposures required can vary, so don’t be afraid to experiment when shooting.
When to Use HDR
The HDR technique can be applied to a whole host of settings and subjects. However, there are several genres to which the technique lends itself in particular…
Landscapes: One of the most popular subjects for the HDR post-processing treatment is the landscape. The ability to handle the dynamic data throughout a landscape shot is of huge benefit when shooting a scene where the sky and foreground necessitate different exposures. In this example, detail on the far mountains and highlights on the clouds would have been lost without accurate HDR processing. For the best results, try to get out there when the sun is setting or there’s a storm brewing!
Architecture: Managing to reveal both the fine highlights and what lurks in the crevices of buildings is a real benefit of the technique, as is the effect on subtle lighting. Next time you’re at church on a Sunday or pop out for a pint, consider taking your tripod and bracketing a few images.
Portrait/Still life: While portraiture and still life images may not be the most conventional of subjects for the HDR treatment, the effect can be remarkable. Subjects shot in difficult or moody lighting often create the best results.
Interiors: Achieving the correct exposure for both the interior and the exterior of a room is nigh on impossible without a sophisticated lighting set-up, yet is easily achieved with HDR. Try wandering around some historic buildings or maybe even just try the technique in your own front room!