Archive for August, 2010

PostHeaderIcon Depth of Field: Why is Less Better?

In the last few years the notion of reduced depth of field has resonated loudly with shooters.  Many shooters opt for 35mm lens adapters or cameras with full- or nearly full-size imagers in order to exploit selective focus as a means to properly direct viewer’s attention inside the frame. The current craze for HDSLRs is an outgrowth of this thinking: that less depth of field is better.

Putting aside for the moment that the greatest film ever made, CITIZEN KANE, exploited maximum depth of field for spectacular effect, there is another reason to consider more depth of field and not less – 3D. In 3D audiences expect objects floating about an auditorium to be in (or mostly in) focus. When backgrounds are blurry or the object plane is not clearly defined, viewers will automatically place these objects at the screen plane, which may not be correct or even logical. Such disparities in logic can be a contributor to the dreaded 3D headache, and so must (usually) be avoided like a plague.

Consider that James Cameron in AVATAR could have used any camera he wanted, but he chose the Sony F950 with 2/3-inch CCD sensors. It turns out that 2/3-inch cameras for 3D applications offer the best compromise for dynamic range, low-light sensitivity and depth of field. That’s not to say that 3D cannot be shot with a RED. Of course it can – and it is. The real issue is the extra time and expense required to achieve the narrow stop and desired DOF, and this means lighting and grip – and lots of it.