The contrast ratio of the luminances of the brightest object to the darkest one, whose details are capable of being discerned/produced. The real world has a luminance range of around 10^-6 to 10^6 cd/m^2, while a computer monitor has a range of around 1-400cd/m^2. In photography, dynamic range is described in terms of E.V. differences (or stops) between the most and least luminous regions of a scene, with an EV difference of one corresponding to a doubling/halving of light and by extension, a contrast ratio of two. Mathematically, contrast ratio = 2^EV. The dynamic range of both sensors and monitors is significantly lower than that of the human eye.
Instructions on how to use the table below to compute the EV for HDR photography:
To compute the EV enter:
1. ‘Shutter Speed’ in seconds or fractions of a second.
2. ‘Aperture’ values.
3. ‘ISO’ values.
4. Click on the ‘Compute EV’ button to get ‘Computed EV’ values.