Photo Answers
Andrew is a highly-experienced writer and photographer – if you have a problem, he is here to help.
Long-exposure dirt
Q Why does sensor dirt show up on my long-exposure landscapes, but not so much on other images?
Charlie Posner
A The length the shutter is open doesn’t affect whether any dirt on your camera’s sensor is visible in the image, but there is another factor that’s often connected to long-exposure photography, which can make it seem as if this is the case. In fact, it’s the aperture you use that will make the most amount of difference. A smaller aperture that gives greater depth of field, such as f/11 or f/16, will increase the chances of sensor dirt being seen.
With a long-exposure landscape image, the photographer is often using these kinds of apertures to help extend the exposure time, since a small aperture lets in less light. The very nature of a long exposure means that areas such as
