If the human eye was a lens, what one would it be?

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techguyone

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I know its a bit of an odd one, but since I first got my paws on a camera and you take a picture of something fantastic, lets say a beautiful landscape and then you see the finished picture and its nothing like how you saw it with your own eyes.

You realise then that your camera lens isn't like your eyes, so is there an 'eye equivalent' lens out there?
 
50mm on full frame is reckoned to give a similar field of view as to what we see.

Different matter entirely for dynamic range and colour spectrum as the human eye has a vastly wider range than any camera/lens

My daughter is an Optometrist and could no doubt state lots more differences between a human eye and the far inferior camera lens
 
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Yup, it's approximately the same FoV as a stereo pair of standard lenses. In terms of resolution, I'm not sure the hardware is that good, so maybe a Lomo/LensBaby but the processing is way better than any computer can manage so combines the 2 fairly low res images into one that appears fairly high res.
 
DizMatt said:
sorry to be pedantic, but wouldn't it be two lenses side by side? :p
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um , no - because he's talking about the human eye singular
 
The reason what you get in the picture isn't like what you see irl isn't so much to do with the lens, it is more that your brain does all the PP on the image as you see the real thing. But as has been said, 50mm on FF is about right for field of view.
 
Surely what you are talking about is the essence of photography. How do I capture what I see before me?

Regarding the field of view, it depends what size sensor you have, but in rough terms 50mm full frame and 35mm on a crop is pretty close.
 
Pretty much as above, but your eyes see in three dimensions and your perception of the subject is also coloured by the combination of your other senses, emotions and the memories it may invoke. No camera is capable of capturing this, and it'll be surprised if the technology will exist in any sort of foreseeable future to do it.

I'm thinking of something like a steam locomotive pulling a train out of a station. You can photograph the scene, and even record the clanking, hissing, noise and the gouts of steam; but not the smell of the smoke and the myriad memories it brings back to older photographers when this was the everyday experience of travelling by train. Or, perhaps a sunset over the sea. No camera can capture the smell of the sea, the grass above the beach, or the warmth and scent of the girl you were holding, just before you took her photograph against the backdrop of the sunset. I'm quite glad this is impossible, some things belong in a world beyond technology.
 
MartynK said:
Pretty much as above, but your eyes see in three dimensions and your perception of the subject is also coloured by the combination of your other senses, emotions and the memories it may invoke. No camera is capable of capturing this, and it'll be surprised if the technology will exist in any sort of foreseeable future to do it.
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A good summary I think.

Just in terms of rendering a photograph, though, surely we have to tutor our vision to see as a particular camera with lens does, as it extracts what is before it in a certain way into a rigid boundary ... ?
 
I've done a couple of environmental landscape jobs for people now and they always specify 50mm in the spec.
 
tijuana taxi said:
50mm on full frame is reckoned to give a similar field of view as to what we see.

Different matter entirely for dynamic range and colour spectrum as the human eye has a vastly wider range than any camera/lens

My daughter is an Optometrist and could no doubt state lots more differences between a human eye and the far inferior camera lens
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It's not so much the lens but the sensor that has the limited dynamic range.
 
Your visual system isn't analogous to a lens. More like the lens, sensor, CPU and software.

Your brain fills in a lot of "gaps" in the objective visual information gathered by your eyes at any given moment. What you "see" is partly what is actually there and partly what your brain thinks should be there.
That's why optical illusions work.
 
I think a 50mm lens is given as being similar to the human perspective. In other words a 50mm lens on full frame, records the scene much as we perceive distance, scale and ratio.

So a 50mm lens doesn't supply us with the same 'field of view' since broadly speaking the human 'field of view' is approximately 180 degrees.

That's how I have always understood it anyway!
 
8-10mm iv heard on a science programme ,complete coverage , central magnification is higher than the edge of the eye .. As the lens is domed
 
Anybody know what the minimum focussing distance is of the human eye ?
 
thewtam said:
I think a 50mm lens is given as being similar to the human perspective. In other words a 50mm lens on full frame, records the scene much as we perceive distance, scale and ratio.

So a 50mm lens doesn't supply us with the same 'field of view' since broadly speaking the human 'field of view' is approximately 180 degrees.

That's how I have always understood it anyway!
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You're right.
Put a camera with a 50mm lens up to your eye. Even on FF it's blatantly not the entire human FoV. However, as you move it in front of your eye your perspective on the scene doesn't change (and it doesn't matter whether it's full frame or not).
35mm on crop-sensor gives roughly equivalent FoV to 50mm on full frame but it DOES change the perspective. Apparent distances between objects will be increased.
 
The human eye has a low dynamic range and short depth of field. It relies on foveation to overcome this. The visual system also saccades (which leads to other problems e.g. not seeing cyclists).

The human visual system is not analagous to a camera. Images created with a camera explore the limits of what a camera can do but don't replicate the eye. Similarly, prints or screens are 2D. The eye doesn't need to refocus so knows any visual depth is an illusion.

Limiting photography to images which kind of match what the eye sees removes huge areas of image making.
 
dinners said:
Anybody know what the minimum focussing distance is of the human eye ?
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It depends on the condition of your eyes, and generally increases as you get older. This is usually associated with your arms growing longer as you have to hold the newspaper further away to read it........:D
 
I cant speak for everyone but most peoples.eyes deteriorate once hitting the thirties.. Focusing on anything becomes a.chor .. Carry a.decent led torch to help you and your lens at night ...and wear your glasses
 
ST4 said:
50mm won't give the field of view on FF the eye does, look at a scene at 50mm through a view finder, then look yourself and you see so much more. I'd say nearer 24mm or even 16mm on 35mm format.
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The human eye actually scans a scene.. it moves constantly around taking in the whole scene in front of you to make a whole image.

I am sure I read somewhere that the actual area in focus at one time is the size of a 50p but your brain stitches it all together
 
There had been a massive debate on this. 50mm was widely regarded In the 1970s. However, following extensive research by some academic body, 35mm is considered by many to be more of the eyes view. 35mm lens is the favourite of film makers for that very reason. Photojournalists have traditionally used the 35mm to put subjects in context with their environment. Leica and more recently Fuji have Used the 35mm on their rangefinder cameras. Street photographers will invariably use a 35mm or 50mm. Again, in the 70s / 80s the 50mm lens was always the kit lens with Nikon / Cannon they were cheaper to produce than zooms. I think this debate will go on for years to come.
 
Blank_Canvas said:
Again, in the 70s / 80s the 50mm lens was always the kit lens with Nikon / Cannon they were cheaper to produce than zooms. I think this debate will go on for years to come.
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Sort of. The term "kit lens" wasn't used in the 1960s - 1980s though. You chose a body, and selected one of the manufacturer's primes in the f1.4 - f2.0, 50mm - 55mm range. The gap between primes and zooms was still quite wide, and these were usually the same high quality, and fairly expensive, lenses that most professionals used, not short, slow, zooms built to an entry level price point.

I agree that the debate will continue. Photography - as we know it anyway - is really just a means of capturing an approximation of what the eye sees and the mind perceives. Just how well it does this depends far more on the photographer than the lens.
 
John Young said:
The human eye actually scans a scene.. it moves constantly around taking in the whole scene in front of you to make a whole image.

I am sure I read somewhere that the actual area in focus at one time is the size of a 50p but your brain stitches it all together
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This is true. Optically, the human eye is rubbish, with only a small area in the centre field of view sharp. The rest of the scene is "constructed" by your brain from memory. Your eye constantly hunts around the scene picking up little details from that small sharp centre zone, so when you look elsewhere, the thing that's no longer in centre is actually blurred, and your brain is simply remembering it. It gives the impression of seamless vision. This is why when you are reading, you get a sense of being disconnected from the world, as your eyes are no longer able to scan or hop around. It's also when you just zone out, and daydream you feel this, as you'll just stare into space, and your eyes are no longer scanning.

Apparently, if you could actually use a human eye for a lens in a camera, it would look something like this..

pzsI4Vp.jpg
 
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It also saccades - it switches off the optical nerve as the eye moves from scan point 1 to 2 and interpolates the difference. This is a big issue for drivers, pilots etc. as it is perfectly possible to look left and right at just the right speed to saccade over a cyclist, the brain interpolates the missing information and you literally don't see him.

Pookeyhead said:
This is true. Optically, the human eye is rubbish, with only a small area in the centre field of view sharp. The rest of the scene is "constructed" by your brain from memory. Your eye constantly hunts around the scene picking up little details from that small sharp centre zone, so when you look elsewhere, the thing that's no longer in centre is actually blurred, and your brain is simply remembering it. It gives the impression of seamless vision. This is why when you are reading, you get a sense of being disconnected from the world, as your eyes are no longer able to scan or hop around. It's also when you just zone out, and daydream you feel this, as you'll just stare into space, and your eyes are no longer scanning.

Apparently, if you could actually use a human eye for a lens in a camera, it would look something like this..

pzsI4Vp.jpg
Click to expand...
 
Pookeyhead said:
This is true. Optically, the human eye is rubbish, with only a small area in the centre field of view sharp. The rest of the scene is "constructed" by your brain from memory.
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Sort of. You can detect novel objects* and movement in your peripheral vision - up to around 180° - even if you haven't looked at them first.

*although you're unlikely to be able to tell what they are with confidence
 
st599 said:
It also saccades - it switches off the optical nerve as the eye moves from scan point 1 to 2 and interpolates the difference. This is a big issue for drivers, pilots etc. as it is perfectly possible to look left and right at just the right speed to saccade over a cyclist, the brain interpolates the missing information and you literally don't see him.
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When I'm cycling I try to make eye contact with the drivers waiting to come out of side roads so I know they have seen me. When I'm driving I do the same. When I'm flying I don't look out for cyclists at all! :D :cow:
 
Pookeyhead said:
This is true. Optically, the human eye is rubbish, with only a small area in the centre field of view sharp. The rest of the scene is "constructed" by your brain from memory. Your eye constantly hunts around the scene picking up little details from that small sharp centre zone, so when you look elsewhere, the thing that's no longer in centre is actually blurred, and your brain is simply remembering it. It gives the impression of seamless vision. This is why when you are reading, you get a sense of being disconnected from the world, as your eyes are no longer able to scan or hop around. It's also when you just zone out, and daydream you feel this, as you'll just stare into space, and your eyes are no longer scanning.

Apparently, if you could actually use a human eye for a lens in a camera, it would look something like this..

pzsI4Vp.jpg
Click to expand...

Hmmm, this is interesting. I'm thinking "this is (partly anyway) why joiners work"!
 
ghoti said:
Sort of. You can detect novel objects* and movement in your peripheral vision - up to around 180° - even if you haven't looked at them first.
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Our peripheral vision, like many other mammals, is extremely sensitive to movement, yes, but optically, it's rubbish outside of that central area.

[/quote]
 
Pookeyhead said:
... if you could actually use a human eye for a lens in a camera, it would look something like this..

pzsI4Vp.jpg
Click to expand...

Looks like we've arrived at a 50mm version of a Lensbaby, then - or did someone mention vaseline?
 
you can do a test if you have a FF camera. Stick a zoom on it, look through the VF but keep both eyes open so you get two images superimposing from the open air eye and the vf eye. Then just zoom till the vf eye image matches what you see in the open air eye and bobs your uncle. Check the focal length.
 
essexash said:
you can do a test if you have a FF camera. Stick a zoom on it, look through the VF but keep both eyes open so you get two images superimposing from the open air eye and the vf eye. Then just zoom till the vf eye image matches what you see in the open air eye and bobs your uncle. Check the focal length.
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Doesn't work that, because most camera viewfinders are around 0.75x magnification. They show a "normal" field of view with a "normal" lens, but much smaller, so if you zoom until the objects are the same size, you'll be using a considerably longer focal length than the actual one that gives the same perspective/field of view.
 
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