Why the depth of field is different
In theory, lenses will give the same depth of field on both FX and DX cameras, so why do FX cameras seem to yield so much less?
Typically, you need to close down the aperture on an FX camera by about a stop and a third to get similar depth of field to the one you’d get from a DX-format camera.
So why is this? It’s because you wouldn’t actually use the same lens on both. On the DX camera, the smaller sensor means that you’d use a shorter focal length lens to get the same angle of view.
For example, if you use a 50mm lens on an FX camera, you’d need to use a 35mm lens on a DX camera to get the same angle of view – and the 35mm lens will yield much more depth of field because of its shorter focal length.
Our infographic below illustrates why crop-sensor cameras keep more in focus.
PAGE 1: What is full frame?
PAGE 2: Lens loyalties with full frame
PAGE 3: Why the depth of field is different
PAGE 4: How to shoot with a full frame sensor
PAGE 5: How a full frame sensor affects your pictures
PAGE 6: Pros and cons of using a full frame sensor