Comparing two different aspect ratios poses some subtleties – when comparing two aspect ratios, one may compare images with equal height, equal width, equal diagonal, or equal area. More amorphous questions include whether particular subject matter has a natural aspect ratio (panoramas being wide, full-length images of people being tall), or whether a particular ratio is more or less aesthetically pleasing – the golden ratio (~1.618) is seen as especially pleasing. Of common display formats,16:10 (8/5) is the closest to the golden ratio, and 15:9 is the closest film format.
Given the same diagonal, the 4:3 screen offers more (over 12%) area, because it is closer to square (which provides the maximum area for a given diagonal measurement). For CRT-based technology, an aspect ratio that is closer to square is cheaper to manufacture. The same is true for projectors, and other optical devices such as cameras, camcorders, etc. For LCD and Plasma displays, however, the cost is more related to the area, so producing wider and shorter screens yields the same advertised diagonal but less area, and hence is more profitable.
The following compares crops of a given image at 4:3 and 16:9, with different parameters equal; note that in terms of subject, the squarer aspect ratio emphasizes the public square, while the wider aspect ratio emphasizes the wide building