In this short video, Gary Fong takes a look at full frame, APS-C and 1.0-type cameras to see how the depth of field is affected at the same effective focal lengths.
The challenge, of course, is that you must change the actual focal length of your lens to accommodate the same field of view on cameras with different sensor sizes. Invariably, this changes the depth of field so that the camera with the smaller sensor appears to have a much greater depth of field, while the full frame camera has a much shallower depth of field.
Gary’s demo is a nice practical demonstration of how these different camera sensors provide different images when shooting the same scene from the same position.
[via ISO1200]
