How does sensor size actually affect focal length?

Focal length?  Effective focal length?  Actual focal length?  Crop factor?  Do you get more reach with a crop sensor?  Is it equal to a longer focal length?  There are some misconceptions surrounding what happens when a lens is used on cameras with different sensor sizes.  Let’s have a look at the differences between a full frame, APS-C and micro 4/3 sensor.

Continue reading →