Height Estimation

The position of a subject in a scene, in particular its height relative to other objects of certain shapes and aspect ratios, may be misleading or at least difficult to estimate. The brain is easily deceived by other visual information as in the diagram here. Have a look at the triangle and estimate how far up from the base towards the apex the red dot is placed. Is it placed 40%, 50%, 60% or 70% up a line from the base to the apex? The truth can be revealed by measuring the physical distance on your monitor.

A curious aspect of human perception is that vertical lines are often perceived as being of greater extent than horizontal lines of the same length.