As explained in this post: In Exercise 11, I wanted a very wide, very straight-on long shot. I tried to do it with two different focal length lenses. Here I’ll compare them.
The shorter focal length lens:
- Includes more of the buildings on the left
- Includes the top of the grassy platform
- Makes the beige building look like it’s bulging a bit
- Looks like it has a high angle on the grass (like the dual high/low angle in one shot phenomenon I observed in my assignment 3)
- Shows more of the ground in general
The longer focal length lens:
- Can see more around the corner of the beige building (eg the phone box)
- Has much straighter lines on the raised grassy platform and beige building
- Makes Brandon look closer to the tree in front of him
- Makes the camera look closer to the ground
- Brought Brandon closer to the bottom of the frame (possibly because it looked more correct to do this while using this lens)
So what I’d like to know is:
Why don’t we always use the longest focal length possible if it seems to give the most ‘realistic’ representation of the space, where straight lines are straight?
After a bit of research online, I found out that a ‘normal’ focal length lens is generally considered to be 35 to 50mm, because it’s similar to what our eye sees. I hadn’t even thought about the link between human vision and a normal camera focal length! I was just thinking in terms of straight lines!
https://petapixel.com/2012/11/17/the-camera-versus-the-human-eye/
With regards to the bent straight lines, I have a couple of ideas why our eyes don’t see this distortion effect. One could be because our brains know what’s going on in a space, and compensates for it. Another could be that we only look at one thing at a time – the things in our peripheral vision, the things that would be the most distorted on a shorter focal length, are not the things that our brain pays attention to. It’s like our attention has a long enough focal length that we don’t notice distortion. In addition, our ability to make sense of the world may also just eliminate this “bent lines” problem.
https://en.wikipedia.org/wiki/Normal_lens
This questionable Wikipedia article raises another suggestion – that it’s related to the fact that the human eye has a concave retina rather than a flat sensor like a camera. Clearly, a projection of a film onto a flat screen is a different representation of the world as what we see in our eyes.
I wonder if an animal whose eyes are more like a short focal length (I have to imagine a fish’s eye is like this) thinks it’s view is distorted, or if it just has a different understanding of the world around it. I suppose the “length” of the “lenses” that are animal’s eyes depend on evolution: animals with “shorter focal length eyes” need to see more information around them but less detail in what’s further away, and animals with “longer focal length eyes” would prefer to see things that are far away more clearly, and can just turn their heads to see what’s to the left and right.
I’d like to end this reflection with this fascinating photo I found of a technique called strip photography: many very thin vertical photos taken in a line, creating a picture which doesn’t come from any one perspective, and consists only of perfect straight lines. I’d love to see a film shot like this… or maybe I’ll get a chance to do it myself one day.
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