HDR Pontiac

My car done in HDR.

First, notice the difference between the two images, both have been HDR'd. The contrast goes to illuminate the differences in tone mapping technique. The first illustrates a more liberal approach, thus creating a more artistic aesthetic. Much like a painting. A more practical use and a bit more conservative adjustment to luminance and subsequent contrast adjustment is shown in the latter.

And I digress....

For those who don't know, HDR means High Dynamic Range. A process by which the combining of digital images taken at different exposures will, in theory, produce an image with a wider dynamic range than a standard JPEG. Dynamic range is the space that exists between shadow and highlight detail. Because of the nature of a digital image sensor, the same dynamic range found in a tone curve of film cannot be duplicated easily because film contains silver halide crystals which have a gradual response to light. Digital sensors have a much sharper response rendering a tone curve more like a straight line rather than a curve. The photosites of a digital image sensor, the body that captures light or photodiode has either an on or off state. When light hits one, it sends a 1 bit or on state to the A/D converter, while sensors that see no light stay at a off state sending a 0 bit to the A/D converter. The number of photosites on a digital image sensor determines the dynamic range so typically full frame digital sensors perform better than APS-C, DX, or crop sensors do because they have greater pixel pitch (photosite physical size) and more pixels. Since most DSLR's on the market are crop sensors of varying sizes, the inherent loss of shadow detail to hightlights and vise versa will remain an issue until better technology is made available. Until then, we have photomatix or photoshop which use programs that merge the images taken at different exposures then average them across the tone curve allowing for tweaking of detail in those critical areas.

This photo, along with the Chattahoochie Shallows shot in my first post are my first attempts at HDR. Enjoy.