Working with Depth of Field...

One of the first things you learn in a basic photography class, after exposure and shutter speed, is depth of field. It doesn't matter if you learned it 50 years ago or 50 days ago. Depth of Field is Depth of Field, analog or digital it is still the same. It is still achieved the same way, we open or close the aperture of the lens to allow the proper amount of light in to the camera to achieve the proper exposure and it also determines how much of the field will be in focus in fron and behind the actual point at which the camera is in focus.

Many folks have lost touch with what it's like to shoot with a shallow depth of field or blur out the foreground and background. The lenses on Point & Shoot Cameras of today are made to get almost everything in focus and Cell Phone cameras all have a fixed aperture so everything is in focus from about 2' to infinity.

I have used many types of cameras in my photographic life, 8x10 & 4x5 cameras, Rapid-Omega, Twin Lens Reflex Cameras, Hasselblad and Mamiya 120 cameras, 120 & 35mm SLR and range finders, 70mm Aerial Cameras, Arriflex 16 & 35mm Motion Picture Cameras, DSLR Cameras and yes I have used a Point and Shoot. On each one of the cameras,, even some of the higher end P & S, you have to use the aperture to set exposure.

Knowing the depth of field is important so you will know how much will be in focus at a given distance. In the past it was more important to know exactly how much DOF you had because we had to wait to see the results. Today the results are immediate, and you can make changes as necessary.

The closer you get to the lens and the wider the aperture, the less DOF you have. The more you move away from the lens and the higher the aperture the more DOF. Simple right...

The photo above of my 15 year old cat, Edy, was taken with a Canon 5D and a Canon 50mm F/1.2L lens wide open at its closest focus point. There is probably .5 cm of the image that is in focus. The Telecaster Guitar was also shot with my Canon 5D and the 50mm f/1.2 @ f/1.8. I lit the guitar with a metallic umbrella and a Canon 580 EX strobe 1/128th power.

A great place to check out your Depth of Field is http://www.dofmaster.com/dofjs.html

It has a calculator so you can plug in the information and it will calculate the DOF. It also tells you the Hyper Focal Distance... That is a story for another day.