What three camera variables affect the depth of field range?

The three camera variables that affect the depth of field range are indeed camera-to-subject distance, lens choice, and f/stop choice. Understanding these factors is essential for controlling how much of a scene is in focus.

Camera-to-subject distance plays a significant role in depth of field. The closer the camera is to the subject, the shallower the depth of field. This means that a narrow area in front of and behind the subject will be sharp, while the surrounding areas will be out of focus. Conversely, increasing the distance from the subject generally increases the depth of field.

The choice of lens, or focal length, also influences depth of field. Wider-angle lenses (shorter focal lengths) tend to produce a deeper depth of field compared to longer lenses, which can create a shallower depth of field. This is due to the optical characteristics of how different focal lengths render out-of-focus areas.

Finally, the f-stop choice directly controls the aperture of the lens, affecting how much light enters and the size of the opening. A larger aperture (smaller f-stop number) results in a shallower depth of field, while a smaller aperture (larger f-stop number) increases the depth of field, giving more of the scene sharp