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01-16-2009, 07:55 AM   #16
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QuoteOriginally posted by Marc Sabatella Quote
In discussions in other threads, the subject of what the natural field of view of the human eye (or eyes) might be. 50mm on film (or 35mm on APS-C) is often quoted
Misquoted actually.... the 50mm on film and 35mm on APS-C, and its relationship to normal perspective and magnification refers to the relationship of the focal length to the media, and resulting with a normal perspective on the final media. (not normal human vision perspective) 50mm was never considered normal on 35mm film, but close enough for discussion, but it was never considered or discussed back then as relating to normal vision perspective. Nikon, Voigtlander and a few others had closer normal lenses at 45mm.

The diagonal dimension of 35mm film is approx 43mm, so then making the FA43 the closest lens in that regard to 35mm film. 90mm on 6x7 film, on APS-C, I think it's more like 28 or 29mm. But that again is a normal lens length in relationship to the media. If you're looking for a lens FOV that approximates your natural vision, then each person being very different (optic nerves, shape and size of eyeball, cornea health, bloodflow in retina, age, genetics, the brain's processing and perception, etc..)

01-16-2009, 07:58 AM   #17
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QuoteOriginally posted by georgweb Quote
Absolutely, a story comes to mind of a tribe from the Amazon jungle. They are said to distinguish and name 40 different colors of green.

Best, Georg (the other)
On that thought, the Native Inuits, have over 100 different distinctions of snow, and the Native peoples of Puget Sound (Seattle, WA area) have over 40 words describing rain. My favorite (from when I lived there) was a word that described the first sunny day following 2 very very rainy soggy wet days in a row, and that word was "Monday"
01-16-2009, 08:01 AM   #18
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QuoteOriginally posted by roentarre Quote
Human vision is using a process called "saccades" to scan different areas of a scene that was stored in an area called superior colliculus. From there, the information is forwarded into processing centre along with other sensory information which include tactile information, smell and hearing etc. All these information are to be "interpreted" by the stored experiences from the past as well as under significant mood status of the individual.

Photography is trying to capture certain visual clues that would evoke a common feeling among the viewers. Thus viewers would share the feeling of the photographers
Always something learned from you!
01-16-2009, 08:22 AM   #19
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QuoteOriginally posted by Marc Sabatella Quote
This can be true, but it of course depends on the magnification of your viewfinder. Also, I'm not sure if this is an inherent feature of all possible 50mm lenses, or if it is somehow specific to the size and distance of the film/sensor/focus screen from the lens.

But in any case, it *has* also been claimed that 50mm reflects the field of view of human vision. For that matter, it's also been claimed that it reflects the "perspective" of human vision, but we don't need to go there again :-) I'm just making some observations about field of view.

If you remember that the human field of vision is acquired by scanning a scene and then building a composite image, the 50mm lens (on 35mm format) is a fairly close approximation to the average field of view.
As you've found out, we are rather tunnel visioned when we are concentrating on an individual object, but if we are looking without concentrating overly on any one thing, we build a much larger field of view.
Lenses in around what is considered normal produce images that we are comfortable with, in that they look like what we see.
If you notice though, normal lenses for medium format represent a somewhat wider field of view than do those for 35mm. The 50 is actually slightly long for a "standard lens".

01-16-2009, 10:59 AM   #20
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QuoteOriginally posted by augustmoon Quote
Misquoted actually.... the 50mm on film and 35mm on APS-C, and its relationship to normal perspective and magnification refers to the relationship of the focal length to the media, and resulting with a normal perspective on the final media.
Right, this was the upshot of a very long and involved discussion here a few weeks (months?) back. But it's kind of amazing the extent to which the idea of "normal" as equating to the FOV of human vision persists - just saw another post making the same claim on another thread earlier today, in fact. Because of the way we tend to scan a scene with eye movements, and the way we filter out peripheral vision from our recollections, there *is* a grain of truth to this, but it's also far more complex than that.
01-16-2009, 12:44 PM   #21
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QuoteOriginally posted by Marc Sabatella Quote
Right, this was the upshot of a very long and involved discussion here a few weeks (months?) back. But it's kind of amazing the extent to which the idea of "normal" as equating to the FOV of human vision persists - just saw another post making the same claim on another thread earlier today, in fact. Because of the way we tend to scan a scene with eye movements, and the way we filter out peripheral vision from our recollections, there *is* a grain of truth to this, but it's also far more complex than that.

I was in a museum in San Diego a few months back and saw some old stereo-scope type of images through a special viewer (where you look through with both eyes. The photos were from around early 1900's and I was very impressed. So someone was thinking along these lines way back then and obviously went way out of their way to come up with that. Pretty impressive, and it did look like my natural field of vision, there wasn't any mention of focal length or film size used, Im sure it was custom large format plates and then the resulting prints were sized properly and such, though...
01-17-2009, 02:43 AM   #22
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QuoteOriginally posted by augustmoon Quote
On that thought, the Native Inuits, have over 100 different distinctions of snow, and the Native peoples of Puget Sound (Seattle, WA area) have over 40 words describing rain. My favorite (from when I lived there) was a word that described the first sunny day following 2 very very rainy soggy wet days in a row, and that word was "Monday"
Hate to burst your greegree, but...

Eskimo words for snow - Wikipedia, the free encyclopedia
01-17-2009, 03:08 AM   #23
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QuoteOriginally posted by rpriedhorsky Quote
Not to threadjack, but I also noticed the other day that the human eye (or mine, at least ) suffers from noise, particularly in low light
There's a name for the phenomenon.

01-17-2009, 03:43 AM   #24
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Marc,

quite interesting observations you made. I tried my field of view looking at a camera test chart and the 'comfortable' viewing distance makes in fact a very narrow angle of view.

But what I also noticed is that I had to get very close to the chart to resolve 2000 lines per picture height with my eyes ... Actually so close, that the angle of view would be at least 70 degrees horizontally ... Maybe my eyes are getting worse.

Imagine watching a print with a horizontal angle of view of 70 degrees ... that's pretty close. Seems like lens resolution is overestimated ...
01-17-2009, 10:07 PM   #25
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QuoteOriginally posted by Erik Quote
As far as I understand this comes from previous damage that the eye has sustained from looking at overly bright light sources and so forth. But as you say, the brain is generally great at filtering it out. It's much the same thing as a slight case of tinnitus in the ear; you can hear it when in a perfectly quiet environment, but otherwise it's impossible to think of.
I'm skeptical. I'm 29 and have never abused my eyes. I do wear contact lenses. I think what I'm observing is simply sensor noise -- why would one assume that a electronic optical sensing system is subject to noise but a biological one is not?

There's other ocular phenomena like "floaters" and flashes which do correspond to damage. In fact, if you get floaters and flashes when you did not previously, you should see your eye doc immediately, because bad things could be happening, like your retina is falling off. Happened to my FW! But a detached retina is a simple surgery if it's caught in time (also happened to my FW, thankfully).
01-18-2009, 06:33 AM   #26
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QuoteOriginally posted by rpriedhorsky Quote
Not to threadjack, but I also noticed the other day that the human eye (or mine, at least ) suffers from noise, particularly in low light -- stare at a white wall and relax, and you can see "shimmer" in the flat areas, just like a digital sensor. Your brain is just really good at tuning it out so you don't notice it normally.

Reid
Reid,

While you may see noise, I don't really think that is what you are seeing. The human brain does not want the eye to fixate on one area because generally there is not much "survival of the species" benefit to it. What is happening is that the brain is firing off an autokinesis (sp?) impulse that make objects appear to shimmer or move so that the eye breaks contact and begins to scan again.

Stephen
01-18-2009, 07:27 AM   #27
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QuoteOriginally posted by rpriedhorsky Quote
I'm skeptical. I'm 29 and have never abused my eyes. I do wear contact lenses. I think what I'm observing is simply sensor noise -- why would one assume that a electronic optical sensing system is subject to noise but a biological one is not?

There's other ocular phenomena like "floaters" and flashes which do correspond to damage. In fact, if you get floaters and flashes when you did not previously, you should see your eye doc immediately, because bad things could be happening, like your retina is falling off. Happened to my FW! But a detached retina is a simple surgery if it's caught in time (also happened to my FW, thankfully).
Thermal noise?

http://marie.ph.surrey.ac.uk/~phs1rs/hecht.pdf

EDIT: Do other people fall asleep so quickly, as to not perceive this phenomenon? Insomnia should cure their ignorance.

Last edited by asdf; 01-18-2009 at 07:36 AM.
01-18-2009, 07:29 AM   #28
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QuoteOriginally posted by SCGushue Quote
Reid,

While you may see noise, I don't really think that is what you are seeing. The human brain does not want the eye to fixate on one area because generally there is not much "survival of the species" benefit to it. What is happening is that the brain is firing off an autokinesis (sp?) impulse that make objects appear to shimmer or move so that the eye breaks contact and begins to scan again.

Stephen
Naaah. Maybe, it's thermal noise.

http://marie.ph.surrey.ac.uk/~phs1rs/hecht.pdf
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