A step wedge is a photographic tool consisting of a series of graduated density steps, ranging from fully transparent to fully opaque. Each step represents a consistent increase in density, which allows photographers to measure and control the exposure and contrast of photographic materials. Step wedges are commonly used in darkroom printing to perform exposure tests, helping determine the correct exposure times and development processes for negatives or prints.
By comparing the resulting print against the known densities of the step wedge, photographers can evaluate how their materials respond to light and chemicals. This is particularly useful in fine art, technical, and black-and-white photography, where precise control over tonal range is critical. Step wedges provide a visual reference that ensures consistent results, making them an essential tool for both learning and professional photographic workflows.