TargetTalk

[visitor]

[-luftskytter]

Maybe it's just evolution?
I would imagine that such things may appear by coincidenceand for unknown reasons. This would then be the "raw material" that natural selection could use for picking the "surviving fittest".
So maybe horizontal pupils were not among the available choices in the gene pool when sidewinders were "developed"?

But come to think of it, maybe the only vertical lines in the world of sidewinders were edible prey? This would mean that horizontal lines are not very interesting for a sidewinder even if they are all over the place.

[ShootingSight]

I am not an evolutionary biologist, so I can't provide any sort of validated answers, though I'll gladly hypothesize ....

I imagine larger cats start getting sufficiently bigger than the grass that this no longer helps them.

Another fact is that goats have horizontal pupils, however a biologist friend of mine pointed out that they spend much of their lives grazing, so their head is inclined 90 degrees forward ... meaning their slits are vertical while in eating mode.

You can mimick this yourself, by squinting. Things get clearer if you squint in a certain range.

[moigy]

I too, am an Engineer, and have worked on low light micro-cameras since the 1960's. One of my Master's degrees is in Statistics.My competition rifle shooting goes back to the mid 1950's, while still in Junior High School.

Two separate thoughts to bring to the table.

1. Why pistols have usually a rectangular front blade to target a circle seems strange. Since my first Wnchester 52C with a small aperture rear sight (Lyman), I coupled aRedfield aperture sight up fromt. I bought a connecting tube (no glass) which eliminated extraneous light. The result was almost like a red dot. The front sight circle permitted just a sliver of light between that front sight and the target. When the sliver was uniform all around, I was in the X zone of the 10. It seems to me the something of that sort mightbe preferable for pistols as well. What say you all?

2. It amazes me that many shooters use formuli for Standard Deviation and Variance (by definition the square of the Standard Deviation), as well as other parametric tests for guns, ammunition, etc. when their sample size is small. When a Normally Distributed activity (something that really needs to be proven by every experimenter) has sample sizes below 30 (some use samples of size 3,5 or 10), the Parametric Statistics need special formulas to be meaningful. The Standard Error becomes, often, larger than the apparent SD. To be really meaningful and accurate, we need to first PROVE that the activity is normally distributed. Then we must use sufficient sample size and appropriate statistical techniques to have valid outcomes. It isn't easy. Ponder it.

[ShootingSight]

On your point #1, you are right on. This is why match rifles use iris front sights.

Your eye has two mechanisms to determine aim. First is how many pixels on your retina are illuminated. You have a pixel about every 1/2MOA to 1MOA on your retina, depending on person. THis is a relatively crude mechanism to judge gaps between the iris and the bull.

You also have the ability to resolve about 16 different levels of brightness, so as the white spece gets bigger/smaller by increments of partial minutes, your eye can still judge if the ring looks slightly brighter on one side than the other, therein lies your accuracy benefit by using an iris.

On your point #2, I spent time discussing my testing with a statistician, and we never resolved how to address it. I only had 3 shooters, so n=3 is certainly not statistically accurate. However since each shooter shot 20 shots for each test condition, you begin to build confidence in each of their groups. At least more confidence than for n=3.

In my case, I'm not sure it matters. No matter what you do, the method gets applied equally to both sides of the test, so the directional notion that one is better than the other remains .... you can only affect if the difference is significant. But here, you come back to the n=3, so it wasn't likely significant in the first place.

[moigy]

On small bore rifle shooting, the NRA specified that only 1 shot per bull be fired. I can see where that reduced arguments with scoring.

Why is it that the National Pistol Matches require more than one shot per bull? I observed my first such match about 10 days ago and at least 5 shots were required per target bull. I do not understand!!!

The iris you sell seems to be placed on or is part of the safety glasses.

How is that superior to a red dot?

How would your system work for someone who has had lens replacement as a result of cataracts?

Would not an iris type system, front and back, modified for pistols produce potentially better scores? Has anyone tried it?

[ShootingSight]

The iris that I sell (will be selling - because I have not updated the web site yet) is a small sticker that goes on the safety glasses. It has an opening smaller than the pupil of your eye, so it will improve your depth of field.

I thought a red dot addresses the depth of field issue by having the red dot appear to come from infinity, so it is addressing the same problem differerntly.

As to cateracts, it depends on what lens you had put in. An option is a fixed focus lens. You could chose between something that was fixed at infinity, and you still needed glasses for everything close up. Another popular option was a 48" fixed focus, which is like a +0.75 diopter lens. This actually works well for rifle shooters, as the hyperfocal distance for a rifle is around 48", so you might be all set. In any event, you can still use a mild lens to tweek your focal point from wherever the fixed lens is to where you want it for shooting.

There are also diffractive lenses that have multiple focal points that people are implanting today. I do not know how these types of lenses interact with small apertures.

[BenEnglishTX]