britinjapan wrote:I know the focal length will increase by the crop factor, but what happens to the F stop?
Just a small clarification, the focal length of a lens NEVER changes. Is a physical parameter and is only one. When shooting with a smaller sensor, the crop factor appears and this generates the "equivalent" focal length in a FF system that will produce the same Field of View.
When you use a DOF calculator, the focal length of the lens is the physical, native, focal length. In the case of the GXR A12 modules, it will be 18.3 and 33mm (not 28 and 50).
This takes us to the other common error that smaller sensors generate bigger DOF. NO! is the opposite. Smaller sensor generate smaller DOF because the CoC (circle of confusion) is also smaller. What generates bigger DOF is the "minuscule" focal length of the lens we use in these compact systems to generate similar FOV than in a FF system.
I mean smaller sensor>smaller DOF
, smaller focal length>bigger DOF
, final effect is that in a compact system we have bigger DOF because the effect of the focal length is stronger than the fact that the sensor is smaller.
Hope I have not confused you more but I think that this concepts must be clear.