Understanding Dynamic Range in Photography

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Dynamic Range

Back

The range of tonal values between the darkest and lightest parts of the subject / environment

Dynamic range can be described as wide or shallow

A very wide dynamic range (very bright areas and very dark areas) are often difficult to capture in one image.

The photographer will often have to decide to show detail in either the dark or light areas of the image.

or - use multiple images and edit in photoshop into an HDR (high dynamic range) file

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Exposure

Back

the light reaching the camera sensor

Front

ISO

Back

Amplifies the sensor's sensitive to light.

lowest value is usually 100 (sometimes 50)

higher values make the image brighter

very high values (above 3200) can make the image appear grainy

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Aperture

Back

circular blades which (which like the iris in an eye) open and close in the lens controlling light entry to the sensor.

Aperture is measured in f-stop.

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Shutter Speed

Back

A set of 'curtains' which open and close revealing the sensor to light coming through the lens.

How long this is open is measured in seconds or fractions of a second

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High Dynamic Range (HDR)

Back

combining multiple exposures for greater detail

Taking a series of images of different exposures allows texture and details to be visible in dark shadow areas and bright highlight areas.

Image shows separate images before they are combined in software such as Photoshop

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Bracketing

Back

Making a series of photographs systematically changing the values to give a range of exposures.

This can be done to ensure a good exposure of an individual image

or

They can be combined to make and HDR image

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Exposure Triangle

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The physical way a camera controls light using:

ISO, aperture, and shutter speed

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Overexposure

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Too much light, resulting in a washed-out image

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Underexposure

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Too little light, resulting in a dark image