Field of view
I've always wondered if human vision has a natural format? What is our field of view?
And how does this fit into the format of prints that we make. Does a 16:9 widescreen photograph appear natural to the eye. Or perhaps a square image?
All depends on how wide apart a person's eyes are, or if they only see with one eye. Each person is different.
I think the problem of approaching this by determing the technical data of our eyes is that our perception differs greatly from what we actually see.
For example, we have a limited depth of field...but because our brains registers sight on a continous basis, we do notice few DoF problems. Our focus constantly shifts and our brains creates a flowing image of the world that is all in focus.
Same for field of view...our eyes constantly scan our surroundings, creating a far larger field of view than we get at any instantaneous moment.
Persistance of our memory of vision maintains a continous mental picture of our surroundings. I am staring at the computer screen, but what is surounding me at the edges of my sight remains as part of my visual perceptions.
I made a 360 degree image using a rotating 120 camera -- printed it out. Very confusing...I could see the image, but I could not wrap my mind around it, so to speak. Thinking in 360 degrees is a whole different story -- I don't think our brains, without a lot of training, can handle it.
I think it was Fred Picker who said that all landscape photographs should be horizontal rectangles because God made people's eyes side by side not one above the other.
The wide aspect ratios like 16:9 seem in practice to be strongly associated with cinema or its home TV/computer incarnations. A while ago I did an informal census of all formats, all media presented to human eyes and by far the most prevalent was "A" format with A4 vertical the commonest size.
Photography, the word itself, invented and defined by its author Sir John.F.W.Herschel, 14 March 1839 at the Royal Society, Somerset House, London. Quote "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..". unquote.
Also think of the fact that the resolution of our retina is not evenly spread. There is only a small angle of view with highest acuity.
Thus we have two imaging devices lying horizontally next to each other, constantly focussing and swinging and tilting and the yielded images `somehow´ overlapping.
Last edited by AgX; 06-02-2007 at 02:12 AM. Click to view previous post history.
Reason: `swinging´ instead of `shifting´
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I don't have the numbers in front of me, but visual field testing is a pretty standard neurologic exam. The bedside test is you have the patient stare straight ahead, then have them identify motion in the periphery. This is used diagnostically for visual field defects. There are more formal "perimetry" testing procedures that include brainstem evoked potentials.
The thing is, this is not really analagous to the field of view of a camera lens. One reason was mentioned, that being rapid saccades or eye movements that dart around to take stuff in, also (as mentioned) getting around issues of DOF.
The other reason is that the field of view covered by our fovea, which is the area of high visual acuity, is extremely small compared with the field of view of our entire retina. In other words, we have a very small field of view that is sharp, but a much larger field of view that is much lower acuity.
This is not a DOF issue, not an optical phenomenon -- it's a neurologic issue in that our retinas, our optic nerves, and everything all the way back to our occipital cortex concentrates attention and resolution on a small area.
Birds of prey have tiny tiny fields of view, but extremely dense photoreceptors -- thus they have incredible acuity, and can resolve things a mile or two away, or see a mouse on the ground as they're darting around a hundred feet in the air.
Edit -- Agx beat me to it.
I don’t intend to beat anyone…
But Maris brought up one interesting aspect.:
Though that Fred Picker quotation seems quite convincing, we are sorrounded by A-verticals.
But why is film horizontal? Why is my computer screen horizontal, and can’t I write decently a letter on it?
I never thought a lot about this, but it could be interesting to look back into history how all these aspect ratios (especially including that vertical/horizontal issue) evolved in man’s cultural development (or movement…) over all kind of outings: painting, printing, photographing, filming etc.
We have a sharp central area of vision of at most 3 degrees and a centrifugally increasingly unsharp field of vision of more than 180 degrees. Eye motion tracking studies have shown that we quickly scan a scene before us with that central sharp portion, with returning emphasis given to points of interest. It is assumed that during that scanning an internal image of our surroundings forms.
I think my brain did a defragmentation of the hard drive overnight. I woke up remembering something about how the Greeks had come up with a mathematical view on this subject. I believe the 35mm format was a "natural" format. Can anyone shed some light on this?
I would like to print photographs in a format that fits in with our field of view. Believing that someone at an exhibition looking at the image would feel comfortable with it on a subconscious level.
It's called the golden rectangle which has a ratio of 1:1.618 according to wikipedia http://en.wikipedia.org/wiki/Golden_rectangle. 35 mm is close at 1:1.5
I don't know that it has much to do with our natural field of view though, but we do find it pleasing for some reason. It's also present in a lot of natural proportions, which may be the reason we like it.