What Does the Term Subject Distance Mean When Talking About Photography?

In photography subject distance is the distance between the focal plane of a camera and the subject being photographed. Knowing the subject distance of a scene can be extremely useful when choosing the correct equipment required to capture an image; When working with subjects at close distances it is extremely important to choose a lens with an MFD which is less than the subject distance (providing the subject will be the object of focus). In this situation a lens with an MFD greater than the subject distance will not be able to fix focus on the subject at the required distance, forcing the photographer to recompose the scene. Subject distance should not be confused with ‘focal distance’, both can be independently altered to change the character of an image.