For simplification, I personally think of stereoscopic deviation as a “percentage” of the image width, but I also try to remember to define the angle of the FOV, otherwise it is all meaningless, e.g. my personal optimum FOV for viewing stereoscopic images is close to 33.3 deg (images with with 3.3% stereoscopic deviation). Definitely some “1/3rd” and “1/30th” laws/rules are in action, here… no doubt in my mind.
BTW, I just found similar “laws/rules” with colors in anaglyph optimization. In the red channel of the left image (in the Channel Mixer), I prefer a mix of 33/100 of blue and 66/100 of green (Peter Wimmer uses 30/70, which not coincidentally, is the same calculations rounded off to the closest 10th… you can’t see the difference between his and mine… mine is just a mathematical calculation).
There is truly something “universal” about the “1/3rd factor” (and 1/30th factor), and the strangest thing to me about that is “three of them” cannot equal one whole part (e.g. 1 / 3 = .333, but .333 * 3 = .999, not 1)… Universal “balance” apparently is not perfectly balanced. 
Tag Archive for 'Optimum FOV'
Click here for a large version of the thumbnail above (suitable for printing).
Typically, the best FOV (field of view) for viewing (most) stereoscopic images is from 30 to 40 deg, with 33.3 deg being the “optimum”. There are a few possible exceptions (e.g. an 80 foot wide IMAX screen with images shot with *special* cameras), but usually, a 30 to 40 deg FOV will provide a decent stereoscopic image viewing experience.
To easily (and fairly accurately) estimate the image viewing FOV, print out this graphic, hold it up to one eye, and point it at the stereo image or image on a screen. You can use it for computer monitors or take it to your next 3D movie or stereoscopic slide show!
My theory has been revisied, so some of the “numbers” in posts before this one may seem a bit confusing.
See:
http://www.puppetkites.net/blog/archives/33
Hmmm. This “whole thing” seems to be “falling right into my lap”.
Don’t you just hate it when this happens? 
120 deg of stereoscopic FOV (field of view) actually includes about 20 deg of stereoscopic peripheral vision (both eyes “at once”, not one).
So, as long as you don’t Super Glue your eyes “straight forward” and staple the back of your head to a wall (in two places), so that you are restricted to looking straight ahead, we poor, wee-little, helpless, mortal humans are left with close to 100 deg of stereoscopic vision!
I don’t have to convert degrees to percentages any more!
We have another “Bingo!”
100 deg / 30 deg = 3.3 deg. That is my definition of “Optimum Deviation”! (1/30th or 3.3%… same thing)
0 deg = zero deviation, i.e. no depth
100 deg / 15 deg = 6.6 deg., i.e. “close to fusion crash” or “stereoscopic failure” due to excessive stereoscopic deviation.
I love it when things keep getting simpler and simpler.
Attn: My recent revision of the theory will have an affect on the numbers in this post!
See:
http://www.puppetkites.net/blog/archives/33
If you look at my “deviation guide” (the piece of paper with “Some Text” written on it and a black vertical bar that is 3.3% of the paper width wide),
http://www.puppetkites.net/blog/archives/31
you will notice that when you move it out to the point where it “just becomes in focus” (per instructions), which defines your stereoscopic depth of field/circle of confusion _and_ 3.3% of your eyes’ stereoscopic field of view (”optimum deviation”) via any one point on that paper, the borders of the paper will then equal 33.3% of your eyes’ stereoscopic field of view. I “knew” what I was seeing, then, and even mentioned it, but just now figured out “why” I was seeing it.
The “correct” eyes’ stereoscopic field of view is 120 deg (not 140). 33.3% of 120 deg is 40 deg. The borders of the paper will (at that point) be 33.3% (1/3) of your eyes’ stereoscopic field of view, i.e. “optimum field of view” for viewing a stereo graphic with 3.3% deviation “on” that piece of paper.
Believe it… or not.
DOF = Depth of Field
COC = Circle of Confusion
FOV = Field of View
deg = degrees
I overlooked something remarkably simple… (doh! sorry, I missed this)
If you make a stereoscopic deviation “gauge” on a piece of paper, and determine what our natural optimum stereoscopic deviation is (1/30th or 3.3% of 140 deg), which is strictly defined, by nature, via our eyes’ version of DOF (which is COC), as I show you how to do, here, the _edges_ of the paper, then, will also strictly define the viewing FOV:
http://www.puppetkites.net/blog/archives/31
It’s that simple! Mathematicians can tell us precisely what that FOV is, in deg. Obviously, it must be somewhere very near 30 to 36 deg, which is (not coincidentally, I’m quite sure) the recommended FOV for home theaters and last row seats for a movie theater.
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