human vision/photography question

Jim10000

Hi!

Can anyone tell me what setting a camera lens should be at in order to match human vision? I have the feeling it's 45 degrees, does anyone know for sure?

Thanks.

DotOrg

45 degrees? that doesn't make any sense. 45 degrees in relation to what?

no lens can match human vision with repsect to how much the eye can take in. a 50mm lens (which is the focal length of the lens) is close to what a human sees. any wider angle lens and objects appear further away, any more telephoto than 50mm and you get a forshortening effect on the picture (objects that are far apart will appear abnormally close to each other)

Jim10000

Thanks Dotorg, that's what I meant really... I should have said mm instead of degrees.

So, if a lens is set at 50 mm it will produce photos which look most like how we see the world normally? (in terms of lack of distortion etc.)

dalk

DotOrg wrote:

a 50mm lens (which is the focal length of the lens) is close to what a human sees.

Hi,

Coincidentally, during a slow day at work, i was reading up on this topic, so I'll pass on what i learned. (To be honest i don't think this info is much use when it comes to actually taking photographs).

Firstly, in the real world there isn't one lens that, in any real way, is close to how the eye actually 'sees'. The way we perceive the world is as much an interpretation by the brain as it is a function of how your eyes work. A result of this is that we generally perceive our surroundings in two different ways (like two separate lens).

The first is a catch-all, non distinct 'wide-angle' view. This is close to 180 degrees and is a low res, not very sharp view of the world. Your subconscious visual system is busy scanning this for points of potential interest.

If something of interest is spotted, the second sharp narrow angle of view 'lens' focuses on this point. A part of the eye called the macula is used. This is the high res part of the retina. Apparently, this narrow view is equivalent to a 200+mm lens on 35mm frame size camera.

So the physical 'in-focus' portion of your vision is actually narrower field of view than a 50mm lens (on a 35mm frame).

To complicate things further the brain also 'zooms' your field of view to try and match what the point of interest is. Think of the difference between your field of view when threading a needle, watching TV, or watching the screen in a cinema.

So how has a 50mm lens come to being seen as having a similar view as an eye?

This seems to be a matter of debate:

1) It is a rough average between the above 2 distinct views.
2) The field of view of the in-focus part of your 'eye' is roughly 30 degrees and the field of view of a 50mm lens is 39 degrees, so they are equivalent.
3) It is the focal length at which the angle of view is the same as your eyes, when looking at a standard 8x10 print at 18inches.
4) Economically it is as wide a focal length that can be built for 35mm frame cameras without having to resort to more expensive lens designs. This means fast cheap bundled lens'.