Sensor shape

[Damien Symonds]

Brian, out of interest, why are cameras still taking rectangular photos?  I understand it was a necessity from the film days, but surely it's time to capture the whole circular (or hexagonal) field of light that comes through the lens, to give more compositional options in post-processing?

Just throwing it out there.

[Brian]

A couple of reasons.

1. People have been creating art in squares and rectangles for thousands and thousands of years. So it's a habit that is not going to change anytime soon, if ever. Even with Caveman drawings, they were usually linear and could easily "fit" in a rectangle or square. It's how human's are "wired."
2. The distortion that is cut off from the round lenses that we use with a rectangle / square sensor. You really don't want 100% of the round images captured. You will be cropping every single photo anyway, probably to a rectangular shape.
3. The rectangle is kinda what the human eye...well human brain, perceives / works with our stereoscopic vision. The brain automatically flips the images (the eyeballs "see" upside down) that the eye creates and cuts off the distortion around the edges. Very similar to how the camera sensor / film cell works and believe it or not, is in a shape of a rectangle. The human eye also sees about 180º Horizontal and 130º vertical, which is basically a rectangle. This in turn also helps humans perceive depth and utilize multiple axis. (X, Y and Z.)
4. A round lens will focus light without geometric aberrations. A rectangular lens that matched the shape of the sensor would distort the image near the corners and if you had a round sensor with round lenses, it would produce the same but different distortion. Think of a really wide fish-eye lens that produces images that aren't pleasing to the human eye.
5. Cost. This is the biggest thing. If you were to have a circular or hexagonal sensor, the manufactures would have to add layers of software in camera to compensate the distortion to get the "look" on how humans perceive things. Why bother creating circle photographs only to convert them to rectangles? If Adobe can't get the "Secret Sauce" from the Manufactures in order for ACR to "Read" the Raw files correctly, I don't see extra software being given away for free either. We have enough trouble as it is with ACR.
6. Golden Ratio. Some of the greatest and best works of art (buildings, sculptures and paintings) use the Golden Ratio. A rectangle is the easiest form / shape to utilize the Golden Ratio when it comes to artwork / paintings.
7. Manufacturing benefits. It's easier to create a bunch of rectangles, and to ship these rectangles and to install said rectangles in rectangle things. Otherwise we are creating circles that will end up in square / rectangle devices. Just think how uncomfortable it would be to hold a round camera. Just like camera plates when photography first started, it was cheaper to create / mass-produce something rectangular or square and even to transport it.

[Damien Symonds]

Fair enough

[Brian]

You are thinking like an Engineer. LOL!!

 

[Damien Symonds]

Well, I was just thinking about all that wasted light coming through the round lens, you know?

[Brian]

The distortion around the edges isn't usable stuff to work with. That's why sensors / film cells are always slightly smaller than the what the lens projects.