Calculadora de Exposição Fotográfica (EV)

The Photographic Exposure Calculator (EV) determines the Exposure Value (EV) from aperture (N) and shutter speed (t). EV is a logarithmic scale representing the amount of light reaching the sensor or film, making it easy to compare different settings. The formula used is EV = log₂(N² / t), where N is the f-number (aperture) and t is the exposure time in seconds. This tool is essential for photographers who want to standardize exposure across scenes or when using filters.

The calculation is simple: enter the aperture (e.g., 2.8, 5.6, 11) and shutter speed (e.g., 1/125, 1/500, 2 seconds). The calculator processes the formula and returns the corresponding EV. Typical EV values range from 0 (very low light) to 15+ (bright light). For example, a combination of f/16 with 1/125s results in EV 15, considered full sunlight. This tool helps understand the relationship between aperture and shutter speed, fundamental for creative exposure control.

Use this calculator when planning photos in varying light conditions, such as outdoors, in studio, or at events. It is useful for determining equivalent settings: if you change the aperture, the shutter speed must be adjusted to maintain the same EV. It also assists in using ND filters, calculating the new required shutter speed. Landscape, portrait, and long-exposure photographers benefit directly from this tool.

Care: ensure shutter speed is in seconds (e.g., 1/125s = 0.008s). The formula assumes a fixed ISO sensitivity (usually ISO 100); if using a different ISO, the calculated EV will not reflect actual exposure without compensation. Remember that EV is a reference, not an absolute value of scene brightness. Always check your camera's histogram for fine adjustments.