PhotogHobbyist Loc: Bradford, PA

I have read numerous articles and descriptions of varioous lens focal lengths and nearly every one describes the 50 to 55 mm length, on a full frame DSLR, as the one that most closely matches the field of vision of the humn eye. I question whether or not that is really accurate. According to medical text books the human field of vision, with both eyes, is approximately 130 to 150 degrees wide, more or less. What I find in lens reviews is the 50 or 55 mm prime lens has a field of view of only around 40 degrees. Why is there such a discrepancy? A wider angle of view, say of a 35 mm on full frame, would more closely approximate the central portion of the viewed area of both human eyes together.

I know there is some edge distortion with wide angle lenses, 35mm or wider, but I would attribute that to the view being focused on a flat plane rather than on a curved plane like the eye's retina. Just a couple random thoughts that flow through my mind.

larryepage Loc: North Texas area

No. But it closely matches the perspective captured by the human eye and interpreted by the brain.

Longshadow Loc: Audubon, PA, United States

(Not the field of vision (view), just the perception of distance (perspective).)

imagemeister Loc: mid east Florida

35mm gets my vote instead of 50 .....

gwilliams6

Quote:
I know there is some edge distortion with wide angle lenses, 35mm or wider, but I would attribute that to the view being focused on a flat plane rather than on a curved plane like the eye's retina. Just a couple random thoughts that flow through my mind."

Just FYI, Sony has patents on and is developing a medium format curved sensor and five medium format curved sensor lenses for it, that will have the same edge to edge sharpness, and will allow lenses to be made more compact.
https://www.youtube.com/watch?v=OTAiHf-5hFA

Cheers

Snappin053 Loc: Southern Vermont

35mm

Longshadow Loc: Audubon, PA, United States

That wasn't quite the question though.

Longshadow Loc: Audubon, PA, United States

What about it.

Are you saying it's your preferred lens or it closer approximates human perception.

Don't forget to specify if it's a 35 on an APSC or FF, as they react differently.

gwilliams6

For my way of seeing, the fullframe 35mm focal length more closely approximates a "normal" human eye field of view, not counting our inherent peripheral vision. I

I have had many 50mm lenses over the past five decades as a shooter, and I have a couple of zoom lenses that cover that focal length now, but dont any longer have a prime 50mm lens for my fullframe mirrorless system. I never reach first for that focal length anymore. I more often shoot wider than 50mm or more telephoto than 50mm.

Cheers and best to you all.

Strodav Loc: Houston, Tx

I thought this video had a pretty good discussion of the topic:

https://www.youtube.com/watch?v=PHcb_UugiPo

E.L.. Shapiro Loc: Ottawa, Ontario Canada

50MM? Good question. Many years ago, I had the opportunity to attend an Ansil Adams Workshop. Mr. Adam's theory was that a focal length SLIGHLY longer than "normal" will deliver a perspective very close to that of the human eye. Over the years, I maintained that theory as my standard practice landscape real estate exteriors, etc.

Another important theoretical fact is PERSPECTIVE is governed by a distance not but focal length alone.

As for the field of vision the 50mm or equivalent for the format in use, in my experience, somewhat replicates the field of view of the human eye. I prefer a 60mm (or equivalent) for landscapes and certain jobs where perspective is important, that's, if space and distance allow.

Modern high-quality wide-angle lenses of moderately short focal lengths 35mm to 24mm, shod no have excessive intrinsic distortion, the curvature of the field, or zonal aberration in athe edges. Forced perspectives are a function of distance. If the camera is kept parallel to vertical lines there should not be too much convergence.

Longshadow Loc: Audubon, PA, United States

On my APSC camera, a while back I ran the zoom between 25 and 75, and found that something that looks 20 feet away with my eye, looks about 20 feet away when the lens is set at about 30-35.
Which x1.6 is about 50. (32x1.6=51)
So yea, I'd say a 50 replicates what perspective the human eye has.

Might not be what some people prefer though.....

(I didn't look at distortion or aberration, or anything else, just what setting made something look the same distance away as my eye saw.)

TomHackett Loc: Kingston, New York

Clearly, a 50mm lens together with a full frame sensor does not match "the human field of vision." But the human field of vision includes central vision (what you're looking at) and peripheral vision, where you may be aware of movement or light or color, but which you can't really be said to "see" in any meaningful way. Try, for example, to read the words on the cover of a book or magazine that is more than a few degrees from the object you are directly looking at. The advantage of having such a wide field of vision is that our eye (brain, really) can become are of a change of light or a sense of movement in the peripheral area and pull the eye toward it so as to see what's really going on there.

Here's a little experiment I tried. I don't know if it has particular value, but I found it interesting. Look directly into the viewfinder of your camera with one eye. Now, with the other eye open and not obstructed, try to overlay what you see with each eye. If one eye sees the subject as larger or smaller, adjust your focal length until they match. For me, that seemed to be about 60mm using a FF sensor. Does that make any sense?

Longshadow Loc: Audubon, PA, United States

Then there's always Giggle:
https://www.google.com/search?q=why+is+50mm+considered+normal&source=hp&ei=xx4mZPi7A_-g5NoP6M2tkAE&iflsig=AOEireoAAAAAZCYs19_h_gEKnyFB-73V4_1JeUiQj_PV&oq=why+is+a+50mm+standard&gs_lcp=Cgdnd3Mtd2l6EAEYATIGCAAQFhAeMggIABCKBRCGAzIICAAQigUQhgMyCAgAEIoFEIYDOgcIABCKBRBDOggIABCKBRCRAjoHCC4QigUQQzoLCC4QgAQQxwEQrwE6CAguEIAEELEDOgUIABCABDoLCAAQigUQsQMQgwE6DggAEIoFELEDEIMBEMkDOggIABCKBRCSAzoECAAQAzoLCAAQgAQQsQMQgwE6BQghEKsCOggIIRAWEB4QHToFCCEQoAFQAFiJhQFg45YBaABwAHgAgAGLAYgB2g-SAQQxMy45mAEAoAEB&sclient=gws-wiz

User ID

Larry nails it right there, first reply in a thread thaz likely to go 15 pages .....

Human field of view or angle of view is ridiculously debatable, but the idea of perspective is pretty solid.

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My personal take is that ~35mm is our view when we casually glance around, while 75 to 90 is our tighter view when something attracts our attention.

I landed at 40 to 45mm for a "natural looking" view using a one-lens kit.

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