In this issue:

Optical system SUMMARY (long)

********************************************************************

[Editor - The following was compiled by 4 of our list members to try to
clear up this topic. There is some excellent discussion on the eye and
sighting system. Since it is so long, I'm sending it in it's own issue.
Hopefully, we can get a similar post for the "Calling the Shot" discussion.]

OPTICAL SHOOTING TECHNIQUES BOTH PHYSICAL AND MENTAL.

>
>CHET (from the original post)
Here is one for you, light travels at the speed of light and when
confronted by a mass, it bends or circles around the mass at a reduced
speed.  
>
>CHUCK, We can choose to go into great depth on how light behaves, or we
can discuss the method of sighting.  We really don't care too much about
the physics of light, but more the workings of the human body.  An
analogy of this, would be how this E-mail system works, each of us
probably has a different E-mail system, we don't care how it works, only
that our E-mail gets to where we want it to go.  Some understanding of
the physics helps and gives a better insight, but it is not necessary to
sending E-mail.
>
>ROSS,  I got a little confused with Chet's explanation of the sighting
procedure.
He seems to be mixing Einstein's Relativity Theory and Young's Theory of
the Diffraction of light.
Lets take Einstein first. He talked about the possibility of light being
bent around large masses. Unfortunately he is talking about masses the
size of the odd Sun or two!! A black bull has basically no mass and thus
does not bend light in that manner.  It can be said the bull has no mass
if and only if it is turned sideways.  This then is nothing more than a
line in the side view.    However, when the opacity of the bull is facing
you, then it is of mass and reacts accordingly.
>
>HENRY,  I'd rather not argue about Einstein or his theories, as I don't
think they are relevant to our problem.  (But, if we do want to discuss
Einstein's theories - it wasn't that the sun was needed to verify a
prediction, it was that using the sun (i.e. a solar mass) was the only
way *at that time* to show a divergence between the predictions of
Einstein theories and those of Newton.  We now have other ways, and it is
now commonplace that Newton's theories don't apply well to speeds near
lightspeed or to environments with truly massive objects.  However, in
the physical world Newton's theories apply very well to rifle aiming and
shooting, and we need not bring in Einstein's theories as the
'improvement' possible falls below what we can see or even measure.)
>
>CHUCK,  This is what I remember from when I was working as an optics
engineer.  The numbers are approximate and for us they are close enough,
I could look up the exact numbers but they wouldn't add anything to the
discussion.  First, let us examine the workings of the eye of a person
with 20-20 vision.  
>
>ROSS,  The focusing and fuzzies around apertures are diffraction
effects.  Not refraction. Vol. 2 No 1 talked about mirage which _is_ a
refraction effect.
Refraction telescopes have lenses as their main focusing mechanism. Light
goes _through_ something can get refracted. Diffraction occurs at edges.
An aperture can be said to be a circular edge.  This 'differential light'
or halo I suspect is a result of the shenanigans that are going on inside
the eye. The eye gets a large part of its resolving ability (that is the
ability to see detail) from a slight shimmering of the whole eye, 
shimmer or shaking is a pretty good description of it. This shaking is
happening all the time and what it means is that the eye is using this
mechanism for the purpose of detecting edges very precisely.  Imagine the
black / white edge of our bull on the retina. The image takes up an
extremely small part of the retinas vision. The black dot covers maybe
500 or so cells max. As the eye shakes this edge turns on and off cells
that are on the edge of the dot very quickly. The visual system picks up
these changing signals and converts them to an 'edge' i.e. the dot.  The
halo that Chet is seeing is the 'overload' signals that the cells are
receiving as they are passed from dark to light and back. It causes a
'reversal' effect. Try looking at a black dot on a white background for
about 30 sec. Then look at a black background. You will see a white dot
at the point of your vision where you were looking at the black dot. The
other effect you will see if you look at a black dot on a white
background is this halo effect. It is the eye drifting off the dot and
leaving the reversal image.
>
>CHUCK,  The halo effect is as Ross indicates. The eye can detect a wide
range in  brightness, if the front aperture is close in size to the bull
the perceived brightness is great.  Has anyone watched a total eclipse of
the sun?  Everything is as dark as night, then as the first ray explodes
everything becomes light again.  The amount of light which passed the
moon is only a fraction of the total normally seen, but it is enough to
bring everything back to day light.  As the size of the front aperture
increases the halo to tend to disappear. 
The eye has a detecting limit of just under 1/20 minute of
angle.  That means that you could just see a ~.3" dot at 50 meters.  But
the eye/ brain work as a wonderful integrator, thus given the right
conditions, you can detect smaller entities than 1 minute.  How much
smaller depends on the conditions.  The eye works on discrepancies, thus
if the contrast is increased such as black on white, we can detect a gap
in the letter "c" of 5 seconds.  If we place a series of equal lines and
spaces, we can detect the absence of one line down to .01 arc seconds. 
Oh, one more thing, the human mind likes order, we like things equally
spaced, we like straight and smooth curved lines, we like things to be
orthogonal.  These are the reasons that the sight of choice is an
aperture.   Sighting is a function of perception.  What I perceive is
different than anybody else, and thus my zero is ½ minute different than,
say Chet's, who is different than Ross....
>
>HENRY,  I believe that some of the important phenomena we are dealing
with, as discussed by ROSS and CHUCK, are those of human perception.  We
know that it is easier to perceive when something is "off center" than it
is to detect an arbitrary position.  We know that contrasting edges are
easier to  perceive than are arbitrary shades (of gray or colors.)  We
use these phenomena to our benefit by choosing target shapes and sight
sizes and shapes.  A round bull in an aperture can be centered very well,
perhaps better than we can actually see the bull (this comes up in long
distance high power shooting) because we have the ability to see an off
center condition and to re-center.  The sharp line/corner targets used in
the bench rest game have been chosen to fit out abilities to use sharp
edges  and to line up with them.
>
>ROSS,  Another thing that happens is because of 
the shaking eye is unable to focus on a point for any period of time
(long being 2  seconds or more), the shooting athlete is unable to focus
on a fixed point dot and try keeping the point you are looking at fixed.
I swear you can't.  The eye very slowly just drifts off.   Sight fixation
is bad in shooting.  The eye loses its ability to pick up the edges very
quickly after 2 seconds if the sight picture is stared at too long. Watch
the elite shooters eyes as they shoot and they are forever flitting
sideways, up an down.  And then briefly coming back to check the sight
picture.  The first second or so tells them whether they are lined up or
not.  If not they reset, flit the eyes and then get back onto it.  The
right size aperture front and rear are a book in their own right so I
won't even start on my ideas here!!
>
>CHET,  Very good.  The above eye function results are correct as far as
it goes.  But you did not include the subject's mental ability to fill and
replace when the physical is remiss in its abilities.  When the subjects
physical eye sees fuzzy outlines the non-dominant takes the image and
replaces the fuzzies with clear and sharp lines that can be used during
the shooting process.  So what has been left out of all of the prior test
by the Germans and others is the impact the mental elements have upon the
shooting process. Of course if you do the research without consideration
of the mental effects then the research is then valid for physical
aspects only, but very misleading or totally invalid in the mental
domain.
>
>CHUCK,  How does the eye "get something out of nothing"?  It is an
integrator, by moving (scanning)  back and forth so that a single ray of
light will excite more than one cone "cell" in the eye.  This works in
exactly the same way that the deep space pictures are gathered, if you
had reviewed the first photo shots from the Hubble Space scope then again
reviewed the later photo shots having been "computer enhanced" you can
get an idea of what the eye and brain do, except in real time.  When I
was young I could "see" a .22 cal hole in the target at 100 yds and a .30
cal hole at 200 yds, when the background was bright.  I was detecting the
hole, as the light was bright and caused an overload on a couple of
cells, and thus was detected, but not seen.  If I stared at the target,
the image would go away, but if I focused in general it would return.
>
>ROSS,  The eye and its ability to get something out of nothing has
fascinated me for sometime. My interest in visual bits was initiated
through shooting and attempting to achieve a better understanding of what
I'm looking at.  During this period, I become involved in the
requirements for the illumination of indoor ranges and during my
investigations, chatted with various lighting experts and scientists at
the National Standards laboratory.  Discovered how the light response of
the cells in the fovea (the central part of the eye) start disappearing 
below about 100 lux. The ranges had levels down to less than 10 lux!
Found out why the UIT stipulate general range lighting of 300 lux and 800
- 1000 lux at the target - Its because the eye is very poor at
accommodating high contrast scenes of greater than about 3 to 1 easily.  
Try looking into the shadows on a bright day without shading your eyes.
Vision is such a frustrating phenomenon that defies logical explanation
but evolution certainly threw up an amazing system!  An excellent
description of the optics of sighting and  the problem that the
eye/visual system overcomes is given in "On the Training of Shooters"
Heinz Reinkemeier, Translated and published by the National Smallbore
Rifle Assn. of Gt.  Britain. 
For instance the image of a bull works out to be about 0.04mm diameter on
the retina. The ring of light around the bull and included inside the
foresight is about 0.05 to 0.08mm diameter. It illuminates about 500
cells.  As the rifle moves, the cells on one side get illuminated by the
moving image and the cells on the other side get shut done from the
image. In effect about 20 cells get turned on and another 20 get turned
off. So the visual system detects the movement by sensing about 40 cells.
A constant pattern of change from illuminated cells to unilluminated
ones. They go on to say that the smallest error that the visual system
can detect is 2.5mm at 50m or 0.6mm at 10m. Smaller errors cannot be
detected by the eye.  They describe an experiment carried out with a
rifle in a vice and pointing at a target. People were asked to align the
rear sights so that the sight picture was "correct" and on the target.
The sights were then misaligned and they were asked to realign them. The
results are interesting. (1000 lux on targets at 50m)
1.	No participant was able to achieve the same adjustment on five
consecutive attempts.

2.	All but two participants succeeded in achieving consistency to within
one click (2.5mm) over five attempts.

3.	No one was able to register errors of less than 1 click.
Other interesting aspects of the experiment were:
A comparison of the adjustments made by each subject shows that every eye
sees differently. Of the 10 subjects none was within 5mm ( 2 clicks )of
any of the others, and differences of 2cm( 8 clicks!!!) were noted. 
There were differences in the selection of both the foresight element and
the rear iris. The "correct" choice would seem to depend not just on the
light but also on the characteristics of the shooters eye.  A precise and
natural position of the head on the cheekpiece of the stock is an
essential requirement for the attainment of optimum performance. If the
head has to be raised slightly, precision deteriorates noticeably.  The
eye functions most precisely when used for a short period 2 seconds or
less.  Some subjects achieved better results without their shooting
glasses(!) No subject had the impression of an absolutely clear sight
picture. Even the person with the best overall objective results spoke of
distortions, blurring and haziness.  These subjects were 1 Olympic
finalist, 5 national team members, the remainder regional representatives
from Germany.  I reckon it is an interesting and very revealing
experiment to do - for new and old shooters alike!
>
>CHET,  The text received from Ross is very good.  The information
clearly indicated the physical eye is incapable of performing at a level
necessary for the shooting athlete.  The stated results also clearly
indicated the shooting athlete is receiving random mental output that is
not acceptable for use during World Class level competitions. This is why
so many have fallen by the wayside during the shooting process.   The
physical eye is incapable of precision shooting on a repetitive basis. 
If this is true, is there another method to be used to augment the eye or
replace its bungling sight procedures. 
Problems:
The physical eye is incapable of performing at an acceptable level and
shooting results is always based upon chance.  The mental eye is always
capable of precision shooting and the athlete seldom understands how to
use the function.
The physical eye can hold or function best in 2 or less seconds. The
physical body also can function at its best in 2 or less seconds and the
total system then commences a rapid deterioration.  Because the shooting
Athletes all proceeded on a physical basis, the mental function is 
accomplished in a random manner.   Therefore, the shooting procedure and
the resulting score will also end with random results.   Also, the system
times will have exceeded the optimum time limits for the eye and body
structure.  This is a small portion of the problem, but all
experimentation to date has clearly indicated that physical aspect is
limited and only goes to a point short of total control and functioning. 
 During every test the mental functional ability was not considered.  
>
>ROSS,  Yes I see where you are coming from. But it doesn't matter how
many times I flap my arms - I still will not fly! My unfeathered arms are
incapable of lifting me from mother earth.  What has this got to do with
eyes? Your comment that this physical experimenting doesn't take into
account the mental part of the system. Of course it doesn't. But it sure
helps to know what the physical limitations are before one progresses to
the mental processes. I predict no-one will fly with the sole aid of the
arms on earth. I also predict that no-one with any level of mental
preparation will fly with the sole aid of their arms on earth. Lets
forget about mentally preparing oneself to fly by those means.  Likewise
from the experiments I described it is pointless for shooters to try and
"correct" errors of less than a click at 50m. Why do they produce sights
with twice or three times the number of clicks? Beats me! 
>
>CHUCK,  Now, for why we have 1/20 minute clicks on sights.  As I
mentioned, the mind likes order, and 5 arc-seconds is 1/12 minutes which
is well with in the eyes ability to resolve.  When you look through the
sights the mind wants order, and naturally tries to center the bull in
the front sight.  The whole thing works like a servo with a feedback
loop.  This is why if you focus on the bull you will have erratic shots,
you can not control the position of the bull, only the sight.  If you
focus on the bull the mind will try to move the bull, which it can't.  
All of this is in the physical domain.  In the mental domain we try to
set the bull in the center of the sight so that the "feedback loop"
returns a zero or nul.
>
>CHET,  Your right about the physical limits of the eye and this we must
live with.  One last comment, please remember the mental functions do not
accept all the theories of the noted persons who communicate them. 
Newton's law does not apply to mental operations.   You said you can not
fly and that is an untruth.  Because you can fly.  You just restricted
your abilities to the one medium that you can not fly in,  but if you
close your eyes and see a pictorial representation of yourself flying
then you are in fact flying.  The human body is nothing more than a
conveyer or facilitator of the cognitive entity.
>
>ROSS,  I disagree that the eyes are incapable of performing adequately. 
The results demonstrate an ability to keep a tight group inside the bull.
 The result of the 1 click error of the experiment was that if one had a
perfect grouping rifle / ammo with a hole 5.6mm across (0mm center to
center) with 10 shot groups, by shooting off the shoulder the group will
expand to 8 - 9mm (2.5 to 3.5 mm center to center). Well inside the bull
at 50m! In my experience the size of the bull seems to be made to be
twice the grouping ability of the best rifle / ammo combination around.
(50m is 10.5mm bull, that gives an effective bull size of 16.1mm, center
to center.  The best groups I know of off the vice are around  6 to 7 mm
center to center. Any group that showed an improvement on that is, I'm
afraid, pure unadulterated statistics, luck, fluke, or as you say random.
And I qualify that with "Given the existing rifle/ammo combinations
generally available".  I bet when it improves they will make the bull
smaller! By my reasoning I would venture to suggest that the ultimate
bull size may eventually get to around 9mm.    BUT,  With good mental
training a shooter is able to utilize the goods at their disposal to
their very limits. That's where your mental training comes in - and only
then. Knowing the boundaries just helps in the process of where to put
the next bit of effort in. For instance, it would be pointless to try and
improve the physical ability to aim the rifle better than a click or so.
So at that point one needs to put the effort into improving the mental
aim of the rifle. 
The interesting thing about life is that it is full of error limits. We
can't measure to a thousandth of an inch with a ruler that has marks at 1
inch intervals. We need a micrometer. We can't measure the size of an
atom with a micrometer - we need an interferometer. We can't measure the
size of an electron. It goes on. You do the best with the tools one has
and just accept those physical limitations. Whichever religion you
support, your GOD made a pretty good job of an eye - but it has limits. 
I have noticed that those shooters who have all the technical aspects of
shooting under control don't necessarily win. Those shooters who go to
great lengths to prepare themselves mentally for a shoot don't
necessarily win either. But the number of shooters who are able to
demonstrate good technical aspects AND prepare themselves mentally sure
pick up more than their share.
>
>CHET,  The first  demonstrated and documented evidence of a mental
shooting technique involved research accomplished by noted scientist
during 1853 and many additional research findings have been published
from that date. Notably, many fine books and research papers were
published in many differing languages during the 1890 to 1940 periods and
now rest  in the stacks of research repositories throughout the world. 
The Mental Art of Competitive Shooting technique was scientifically and
psychologically well established by the early 1900's. 


We all hope this discussion has helped those who are always striving for
knowledge about the shooting sport and International competitions.  The
above text was authored by Ross Mason(New Zealand), Chuck
Whipple(Washington State),  Henry Schaffer( North Carolina), and Chet
Skinner(Tennessee).

******************************************************************
End of UIT Mailing List #4

Michael Ray - Systems Engineer
Rose-Hulman Inst. of Tech. Rifle Coach
UIT Shooting Page - http://www.geocities.com/Colosseum/1190/index.htm