A Site for Photographers by Photographers

Community > Forums > Casual Photo Conversations > Human eye and Camera, the...

Human eye and Camera, the basic differences:

Dilip Kumar Singha , Oct 26, 2008; 01:06 a.m.

We view through our eyes (the best available optical device in the world) and process / visualize the image through our brain (the best available processor in the world) and our sense is tuned to this combination through out our existence, also we view through our lens, take snaps and further process it in computer. What are the basic differences between the two and which of the differences make a snap striking and appealing?


    1   |   2   |   3     Next    Last

Felix Grant , Oct 26, 2008; 04:31 a.m.

While the brain, I agree, /is/ the best available processor it's that fact alone that makes human vision so good. The eye itself is /not/ the best available optical device by a very long way – it only appears so because the processor woks miracles of synthesis to clean up the information.

For example: the human eye resolves, at best, about 8 lines per millimetre – and over most of its field of vision much less than that, and it declines with time from about age 20 onwards. A 35mm film camera, by comparison, resolves around 80-100 lines per millimetre in average hand held circumstances. The rich and detailed vision we enjoy relies on the eye always being on the move, capturing partial and low grade images which the brain combines in order to produce an enhanced final view of the world.

I'm not just saying that for the sake of disagreeing –it's relevant to your main question.

What makes the difference in a "snap"? Precisely, in my opinion, that: it is a snap, a single moment fixed, which the eye alone cannot do. We see, in a real sense, in digitally synthesised video; photography cuts across that by presenting us with the impossibility (in nature) of high fidelity stillness.

Colin Carron , Oct 26, 2008; 04:40 a.m.

Camera usually gives a rectangular field of view of about 20 - 80 degrees while the eye is about a kind of elliptcal 180 degrees.

Camera is broadly speaking evenly sharp over the whole frame while eye has a small sharp central area surrounded by a wide area which is less sharp.

Camera can usually adjust focal length while the eye cannot.

Camera media can cope with an exposure range of maybe 7 stops if you are lucky while the eye can usually cope with a wider range at any one time and usually a wider absolute range of brightness. .

Camera is usually two dimensional while eye + brain process the image to a three dimensional image.

Camera gives still image (well, a still camera does!0 while eye + brain create a movin image.


Chris Waller , Oct 26, 2008; 06:08 a.m.

Mine used to be among the 'best optical devices in the world', but they are now less than optimal, even discounting the color-blindness I've always had. Now. I need +1.5 - 2.00 diopters to read newspaper print. Glass doesn't, as far as I know, suffer this decline after five decades or so.

We have two eyes and see via stereoscopic vision - the camera looks at the world through its single (usually) 'eye'. We scan with our eyes - the camera takes a fixed view. Much of what we perceive is a monatge of images over time, just a few seconds, but is why the landscape I saw as I drove along the road cannot be captured with a camera. Perhaps there is more to Winogrand's apparently flippant answer to the question, "Why do you take photographs?" when he responded, "To see what things look like when they're photographed."

Bruce Margolis , Oct 26, 2008; 07:22 a.m.

Interesting question. Really interesting how we process with our brain, not through our eyes.

Good peripheral vision would be maybe 180 degrees, though it is a bit less for most people. That is what our eyes see. However, when you view a photo on your computer, for example, the brain kicks in and focuses on the image, not the surrounding stuff.

For those purists who believe photos should reflect 'reality,' I guess that means everything should be photographed with a lens wide enough to pick up the entire 180 degrees. Hmmm, never thought of it that way before.

Rashed Ahmed , Oct 26, 2008; 07:25 a.m.

Digital images are more sharp ( if sharpen in camera or in PC ) then your eyes can see naturally !

Noel Gutiérrez , Oct 26, 2008; 09:34 a.m.

If we try to simile the human eye in a sensor for a super camera, today this would be impossible. I guess the nearest thing to it is a large format camera in analogues or one of those Nikon's 21.1 MP. I saw that to make the human eye in a digital sensor, this one, would need about 576 MegaPixels. So I guess it is impossible until maybe lots of years.

Kelly Flanigan , Oct 26, 2008; 10:04 a.m.

Real world folks rarely get 50 line pairs per mm on 35mm film; even on their good negatives. Thats because of camera shake; miss focus; they dont use fine grain B&W films; they dont always shoot at F8 ish; and they almost never shoot 1:1000 contast portraits; sunsets; group photos etc. A less maked believe number is say 35 as a tyical number and 50 best case; and 100 a 1 in 100,000 case with the camera on a granite block; with times lights and a 1:1000 contrast object.

Kelly Flanigan , Oct 26, 2008; 10:10 a.m.

The resolution of the human eye is only sharp over a very small angle; ones eye has to rotate to see fine details; ie very very poor off axis. This the "megapixle" level of the eye is really very very low. Its more like two devices; a super super wide angle of say 180 degrees to that resolves very little; less than a Barbie Cam; and a very narrow moderate high res camera thats only got a few degrees where its sharp

Kelly Flanigan , Oct 26, 2008; 10:19 a.m.

The eye is more like a Planet/Martian rover's eye were there is a low res wide angle to get the jist of whats out there; ie where to point the high res camera. With your eye you rotate it to see the fine details of an object

    1   |   2   |   3     Next    Last

Back to top

Notify me of Responses