Stretch your camera’s dynamic range with High Dynamic Range photography.
HDR photography involves taking multiple exposures of the same image while adjusting the f-stop on your camera, which regulates the amount of light passing through your lens. It’s usually best to use a tripod so the image composition is identical in each shot.
Take a photo with your f-stop at a normal setting, then take one underexposed by one or more stops and one overexposed by one or more stops. These images can be combined in Adobe Photoshop Lightroom for a much wider dynamic range than is possible with a single exposure.
Camera setting values for HDR.
Some cameras have an HDR mode you can use to automatically follow this process and provide a wider dynamic range. If you’re setting up your camera manually for HDR photography, set your camera to:
- Aperture Value (AV) mode. This setting will let you control the aperture of the exposure (though remember to keep it the same for each shot to preserve depth of field). When selecting your aperture, consider that f/5.6 will let in a considerable amount of light – making it great for capturing landscapes and cities.
- The Time Value will keep the shutter speed consistent. Fast shutter speeds will effectively capture quick-moving action, while slower speeds can introduce blur.
Illuminance and reflectivity in HDR.
The levels of light in a scene can significantly affect your results in HDR. If you’re photographing a scene with high reflectivity (for example, an ocean) the real-life dynamic range may exceed your camera’s. That’s what makes accurate light measurement so important when assessing dynamic range and setting aperture. Measured in candelas per square metre, illuminance reads more strongly in direct sunlight than starlight. However, it’s not as simple as telling night from day – on a partially overcast afternoon, the presence of both direct and obstructed sunlight would greatly increase the dynamic range of a scene. Remember that your camera’s in-built light meter will only measure reflected light, rather than light from the source itself (AKA incident light).
Dmax and Dmin.
Dmax and Dmin measure the density of an image - 0.0 is pure white, 4.0 is pure black. Various hardware used for producing images have different Dmin and Dmax ranges – and it’s important to bear this in mind when shooting, as it will affect quality and crispness of the end product. For example, most printers have a Dmin and Dmax range of 2.0 (the difference between the brightest white and the deepest blacks it can produce) and often won’t be able to replicate the variance in illuminance you may have captured on your camera.
Discover how to capture HDR images.
Learn how much to vary your f-stop, how many exposures to use, and how to merge to HDR.