In addition to maintaining the traditional shape of film, using a rectangular sensor also leads to better pictures. A round camera lens does produce a round image inside the camera. ... This is because light must be bent more to reach the outer edges of the circular image.
First, it’s a known fact while lenses capture an image throughout the circumference of the glass, any degradation occurs on the outer parts of the image, hence cutting off those parts results in a sharper overall image in a rectangular format. This leads to the next question, “Then why aren’t images square?”
Another good question as it makes sense to trim off the degradation equally from all sides, which results in a square. However, any designer will tell you that a rectangle is more pleasing to the eye, since we tend to naturally see more through our own eyes in a horizontal format. This rectangle format also allows us to shoot the more powerful vertical.
Though there have been square format cameras in the past, like the Kodak 126 Instamatic camera, basically a squared 35mm format, and the more commonly known amongst professional photographers was the medium format, 2¼ square format.
I myself used the square format back in high school as a photographer. The camera of choice for my photojournalism instructor for his photographers was the Yashica Mat 120G medium format camera. The square image the camera produced was 2 ¼-inches square on each side, many times larger than a 35mm negative, allowing us ample room to crop out rectangle images in either a horizontal or vertical format.
So the more I thought about that question, I decided to come up with some answers of my own (in a humorous way) and a few other questions I’d love to know about the answers myself. So first, here are a few of my assumptions on why we capture in a rectangular format vs. a round format, though we use round lenses:
• Rectangle lenses would provide lens barrels that would be difficult to focus. Imagine turning a rectangle, focusing ring, not to mention attaching rectangle filters.
• Finding picture frames would become interesting, now we’d have different circumference size frames.
• There would be tons of paper waste because paper is in a rectangular format, so round prints would create a non-green environment.
• Round computer monitors to view photos doesn’t make sense.
• It becomes difficult to properly align round images in frames and hang them exactly the way they were captured.
• If video adopted round formats, tubeless televisions today but appear as one large tube.
• Our smart phones would become round to view the images properly too. Now can you imagine round Instagram photos instead of their current square format? Even worse, if you dropped your phone can you picture it rolling down hill?
• Billboards would become round adding a tunnel vision perception.
• If theater screens were round would we be sitting in tunnels viewing movies instead of rectangular theater rooms? Can you imagine the acoustics alone?
• The Rule of Thirds would require a revision.
Now here are some of my questions about other things in life:
• Why is bacon in the U.S. cut in rectangular strips and Canadian bacon in round pieces?