If
we take 2 images of the same subject from the same
location - one with a 19mm wide angle - the other
with a 300mm lens. And then enlarge up just the section
covered by the 300mm lens in the image taken with
the 19mm lens - we actually find the perspective is
the same.
However
if we move closer to the subject so as the 19 mm lens
fills the frame in the same way as the 300mm lens
we find quite a different relationship in terms of
perspective.
Of course as longer focal length lens have less depth of field - this also has an effect on the amount of depth of
field or areas in focus in the image.