Depth of field has the following features 1. Larger F-numbers give greater depth of field. The more the iris is stopped down the greater the depth of field. Shorter focal lengths give greater depth of field. Greater subject distance gives greater depth of field.
Depth of field is greater behind the subject than in front.
M.O.D. Generally used for very close-up applications. Not recommended for zoom lenses due to loss of tracking. The drop of the F-number of a while zooming at full aperture. The entrance pupil of a zoom lens changes in diameter as the focal length is changed. As you zoom towards the telephoto end, the entrance pupil gradually enlarges.