From a physics reasoning, it's the distance from the object to where the object is observed, and therefore the sensor. Don't see why this logic is not applied to cameras that have always been so. Of course, I can't say for sure, so just why am I trying to answer your question?
on top of your camera you should have a little circle with a line through it,this is where your sensor is in your camera. if you were measuring for accuracy this is the point you would start from,to answer your question yes it is from this point to the front of the lens.hth mike.![]()
Minimum focus distance (MFD) is from the focal plane of the camera to subject as others have said and minimum working distance (MWD) is from the end of the lens to subject.

Hi Lucy
Canon give the minimum focus dist for the 100mm macro as 31cm. I just tried mine with a tape and its about 15cm to the front element so it must be to the focal plane.
BTW you still doing the macro water drop collisions?
on top of your camera you should have a little circle with a line through it,this is where your sensor is in your camera. if you were measuring for accuracy this is the point you would start from,to answer your question yes it is from this point to the front of the lens.hth mike.![]()