Difference in short focal length big nose syndrome

[ToddnTN]

I would ask this question becasue almost all of the books and theorys floating around out there relate to a full frame camera. It is nice to know how these relate to the crop sensor camera that I have. For example, I have read that for a full frame camera the 85mm focal length is a good length for head shots. I need to know how that bit of information relates to my crop sensor camera.

 

[jaomul]

Is the 4/3rds or micro 4/3rds the same or does its design make a difference. 25mm seems a portrait focal length on a micro 4/3rds but 25mm on a fullframe would create an unflattering portrait or does it work out due the fact your standing further back to fill the frame?

 

[Gavjenks]

Sensor size makes no difference. Distance, only distance.

Sensor size, like focal length, is indirectly related, insofar as with a larger sensor, to get the same framing of the face with the same lens, you're going to get closer.

But in reality you don't really USE the same lenses with a full frame, so it ends up not really mattering.