In the screenshots below, the image on the left is overexposed, resulting in blown out highlights and loss of detail in the critical bright parts of the tower (antenna panels, pole, etc.). The image on the right is underexposed, resulting in loss of detail in the dark parts of the tower (cables, shadow side of the tower, etc.).
The most common cause of exposure issues is that pilots fail to adhere to the easy step-by-step instructions for setting exposure outlined in our capture guides
In addition, particularly high-contrast light can result in over- or underexposure due your camera’s limited dynamic range. Dynamic range is defined as a camera’s ability to simultaneously capture the darkest and lightest tones in a scene. Cameras with a high dynamic range capture more shadow and highlight information than cameras with a low dynamic range. If, in a given scene, the difference between the brightest and darkest areas is too great, the camera cannot capture the full range of tones and, depending on the exposure settings, either highlight or shadow detail is lost.
As a rule, our processing software is better at dealing with too dark shadows than with blown out highlights. For this reason, the histogram-based procedure for setting exposure described in our capture guides is designed to avoid overexposure while, at the same time, making optimal use of your camera’s full dynamic range to capture as much shadow detail as possible. The following scenarios explain how to expose correctly in two typical high-contrast situations.
- Very harsh light when the sun is low (early morning, late afternoon, and in winter): If possible, avoid capturing when the sun is low (i.e. fly around noon when the sun is near its zenith). Particularly undesirable are backlit situations (i.e. the camera pointing into the sun, which can also cause lens flare). If you have to capture during winter at high latitudes, preferably fly on an overcast day with diffuse light. If you cannot avoid capturing in high-contrast conditions, expose so that the brightest parts of the tower are as bright as possible (but without overexposing them).
- Rapidly changing light on cloudy days, with the sun shining but frequently disappearing behind clouds: It is best to avoid capturing in this situation. If you must fly, make sure that you set exposure when the sun is out (i.e. not when it is behind clouds), then leave exposure unchanged, even if the sun disappears behind clouds.