A Lesson in Depth of Field, Part 1
When you talk about depth of field and how to achieve the amount you want in a photograph, most people have no idea what you are talking about. I am going to try to explain it to you and show you two examples. I won’t go into the technical points, but will attempt to make it easy for you to understand. Depth of field is, in plain language, the depth of the focus in your image; that is, whether only one thing is in focus in your image or everything is in focus.
A full depth of field…
This image was shot at f/29 at 1/13th of a second (the exposure time). The aperature (f/29) is very small. Think of the lens as an eyeball and the pupil is the aperature. Depth of field is created by the size the aperature (your pupil) in your lens. The larger the pupil, the more light is let in (ever had your eyes dilated?). On a lens, the more light that is let in, the shallower the depth of field (you can’t see clearly). Aperature sizes have a large range. The smaller the number, the larger the opening and the shallower the depth of field. Sometimes it is hard to remember which aperature gives you which results! I will continue this tomorrow and hopefully clarify this some more.