Perspective : visual – The way in which objects appear to the eye, Representing the effects of visual perspective in graphic arts,
Perspective photography distortion is determined by the relative distances at which the image is captured and viewed, and is due to the angle
of view of the image (as captured) being either wider or narrower than the angle of view at which the image is viewed, hence the apparent
relative distances differing from what is expected. Related to this concept is axial magnification the perceived depth of objects at a given magnification.
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with my finger and hand
and with the wall!