How does that explain the centuries of predominance of shapes in the range 5:4 to 3:2, with many artists over that period making their own canvasses and so free to choose their shapes? How does it explain the predominance of choice of shapes in the range from square to about 7:5, on the other side of 3:2 from the Golden Ratio? There are a great many sizes and shapes of canvasses and drawing pads in art supply stores, far more variety than photographic printing papers: are you suggesting that despite an alleged strong artistic preference for about 8:5 image shape, no maker of canvasses or drawing paper has chosen to offer such a shape (or if they do, none of the art supply stores I visit has chosen to stock such an item.)
There is perhaps nothing aesthetically particular about the aspect ratio choices of images dimensions that people make (which is not the same as compositional choices within the frame), if we are to believe this study:
Beauty in abstract paintings: perceptual contrast and statistical properties Finally, in agreement with previous findings (McManus, 1980; Russell, 2000), we found no correlations of beauty ratings with the aspect ratio of the abstract artworks.
I do not know if aspect ratios of abstract artwork is appreciated much different from those of figurative art. I suppose it's even harder to get objective results due to sympathy/antipathy towards recognizable subjects.
Maybe more mundane factors play a role, such as habit, copycat behavior, or what have you. Also remember that e.g. the famous Night Watch by Rembrandt was
trimmed on 4 sides, presumably to fit the wall space at its new location, talk about mundane...
As a mathematician, I well aware of the fascinating mathematical properties of the Golden Ratio; but between scientists, I ask you to provide an evidence that "rectangular still image artists" actually gravitate towards that shape, because all the evidence I have gathered points in a different direction. If I had to choose an empirical measure of "central tendency" it would be about 7:5.
Apparently there is no conclusive evidence available in modern research, for either or any aspect ratio to be a clear winner. Again, that's not the same as compositional ratios within the frame size.
Ming Thein also has some
useful thoughts about aspect ratios and compositional theory. He states that
"the aim of this article is to focus on understanding the compositional impact of different aspect ratios, and more importantly, how to pick the right aspect ratio for a given subject".
It's that last part, "how to pick the right aspect ratio for a given subject" that resonates most with me. It is also what I like about stitching, the freedom to fit any aspect ratio frame around the subject. The subject is key, the frame is secondary (not unimportant but secondary), especially in the case of stitching for resolution, not necessarily for Field of View. The framing is used to augment the composition, e.g. by giving more weight to the sides or to the height.
Ming Thein also touches on why images with portrait orientation tend to have a more square aspect ratio, to do with the more challenging composition given our horizontally place eyes that have to scan the image in tandem. Maybe your study included many verticals, which would likely have shifted the weighting towards more squared aspect ratios.
Cheers,
Bart