When you are taking a photo where some parts are very bright and others are very dark, what photo technique lets you capture detail in both areas?

The photo technique that lets you capture detail in both very bright and very dark areas is High Dynamic Range (HDR) photography. This technique addresses the limitation of a camera's sensor, which has a narrower 'dynamic range' than the human eye. 'Dynamic range' refers to the total range of light intensities a camera can record from the darkest discernible shadow to the brightest discernible highlight within a single image. When a scene contains areas significantly brighter and darker than what a single exposure can capture, a standard photograph often results in 'blown-out highlights' – areas that are pure white with no detail – or 'crushed shadows' – areas that are pure black with no detail. HDR photography overcomes this by capturing multiple individual photographs of the exact same scene at different 'exposure' levels. 'Exposure' is the amount of light allowed to reach the camera's sensor, determining the overall brightness or darkness of an image. Typically, at least three images are taken: one 'underexposed' to properly capture detail in the brightest parts of the scene, one 'normally exposed' for the mid-tones, and one 'overexposed' to capture detail in the darkest parts. The underexposed image captures the highlights without them becoming pure white, the overexposed image captures the shadows without them becoming pure black, and the normally exposed image captures the mid-range details. These multiple exposures are then combined using specialized software through a process called 'tonemapping.' 'Tonemapping' is the technique of mapping the expanded range of light and detail from the combined images into a narrower range that can be displayed on standard screens or prints while preserving local contrast and visibility across the entire light spectrum. The software intelligently selects the best-exposed parts from each individual image – for example, taking the detailed bright sky from the underexposed shot and the detailed dark foreground from the overexposed shot – and blends them seamlessly into a single composite photograph. This final HDR image effectively extends the perceived dynamic range, making details visible across both the brightest highlights and the deepest shadows simultaneously.