Photography Post: Thoughts on Perspective & Focal Length

The 'nifty fifty' view, taken at 51mm equivalent (34mm APS-C)

How much do photos show a landscape as it actually appeared, that would look the same to someone else standing in the same spot?  I don’t mean the same colours, the same light, the same sky,  of course. They change all the time. I mean the perspective, the relationship between different parts of the image. If there’s a tree in the foreground and hills on the horizon, is the scale of both the same in the photo as in the actual view?

It all depends of course on the focal length of the lens. The wider the lens the more of the scene is in the view but the smaller distant objects appear and the larger close ones appear. The opposite happens with a longer focal length.

So what’s the focal length that’s closest to what you actually see? Traditionally it’s 50mm, the ‘nifty fifty’ in the full frame/35mm format. When I was learning photography, with a 35mm film camera, I read this in many books. I never really thought about it though. I just accepted that if all these photographers said it then it must be so. But must it?

Recently I read a number of online articles, like this one, about focal length and human eyesight and began to wonder.  In different places I read that 43mm and 70mm were correct, not 50mm. They couldn’t both be! I looked at some of my photos of views I can see from home taken at around the equivalent of 50mm (33-36mm on my APS-C camera) and then looked out of the window. The mountains in the distance looked smaller and further away in the photos (see picture at the head of this article).

How it looked to my eyes. 73mm (49 APS-C)

A practical test was needed. I went outside to see which focal length looked the most accurate to my eyes. I picked a spot with some stones not far in front of me so I could check their size against the trees in the mid ground and the hills in the distance, I used a zoom lens (all the images in this piece were taken with a Sony 18-135 zoom lens) and looked at the view and the camera screen while zooming  the lens until the proportions looked the same for both.

When the image in the viewfinder and what I could see matched near enough I pressed the shutter. The focal length was 73mm. That’s 49mm on an APS-C camera so 50mm is the right focal length for the world to look as I see it! But not in full frame/35mm terms.

If someone stood on the same spot and looked at that view they would see everything in proportion as in my 73mm photo.

Cropped wide angle image

Does that mean having everything in proportion results in the best photograph? Only if that’s what you’re trying to capture. I don’t think the 73mm image is the best from this spot. Or at least it’s not my favourite. I prefer a wide angle image cropped to a panoramic format. I could only see it looking like that through the lens though. It's worth nothing that the dramatic view in a photograph may not look just the same in reality!

Put of curiosity I am going to go out with just my 50mm lens (75mm equivalent) and see what results I get.

Here are some more photos taken from the same spot at different focal lengths.

31mm (21mm APS-C)

111mm (74mm APS-C)

202mm (135mm APS-C)