Color of rear iris disk

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Albert B

Color of rear iris disk

Post by Albert B »

Has anyone experimented with different colors of the rear iris disk?
I have done some tests and found that a darkish blue gives optimum sightpicture (for my eyes), especialy when the shooting range and firing point have a low lighting condition.
I used to have a reddish-brown irisdisk but that color distracted my sight outward from the center if the iris, while the blue color draws the sight inward to the center. Also the blue gives a restfull color for my eyes while the reddih-brown works agressively.
I did some research on the internet and found that the cones (used for color) in human eyes needs a high level of light in the red spectrum to work properly. In low level light situations the rods work best and they operate in the blue spectrum.

Any comments apreciated.

Albert B
(The Netherlands)
peepsight
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Post by peepsight »

Hi Albert

You have done some interesting research on these coloured rear iris rings.
I watched a few ISSF TV videos of the top shooters competing around the world and noticed one or two using white rings, a few used other colours and a lot used none at all.

Its often said that shooters will use different coloured rings depending on the range lighting and their mood at the time.

My old AHG iris has a permanent orange coloured iris back disc and seems to work fine for me but i suspect orange won't suit every shooter.
I'm very interested in the concave mirror rear iris but have never used one so I cannot make a comment. I would be interested to hear if any body has tried these out?

Interesting subject.

Peeps
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Jason
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Post by Jason »

What I've always wondered is if (or how) coloured discs and filters affect people who are colour deficient -- like me.

If the eye still functions normally but it's my brain that can't distinguish between certain colours (red/green in my case), I should probably still be using coloured filters and discs, right? But how do I know which one is best if I can't see the difference?

Is there a general rule of thumb about when you should use a specific coloured filter (or disc)? For example, yellow instead of amber? Or grey instead of brown?

Jason
keithwwalker
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Post by keithwwalker »

Jason wrote:Is there a general rule of thumb about when you should use a specific coloured filter (or disc)? For example, yellow instead of amber? Or grey instead of brown?
Jason
Download the Gehmann catalog on pdf:
http://www.gehmann.com/downloadable-ite ... i-engl.pdf

Page 7 of the catalog has a table entitled:
PRIME EFFECTS OF COLOUR FILTERS ON YOUR SIGHT PICTURE

Simalarly, starting on page 28, the MEC Centra catalog has info interspersed troughout:
http://www.mec-shot.com/products/catalo ... ade1442592
http://www.mec-shot.com/downloads/catal ... ompete.pdf

MEC Centra will also mail you a printed catalog freakishly fast. I got one in 2 days from Germany, now that's service!

MEC Centra also has some books on shooting in English that sound interesting.

kww
peepsight
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Post by peepsight »

Guys
I may have been under the misapprehension that the original poster was talking about the different coloured bezels that fit over the rear iris eye piece. These are another subject entirely but never the less very interesting.
Yes, Gehmann do explain the effect of different colour filters but bare in mind that they also reduce the amount of light entering the eye.

The advantages and disadvantages are explained in some detail in the MEC publication 'Air Rifle Shooting'.

Try it and see is the only way to make your mind up.

Peeps
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Jason
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Post by Jason »

Yes, that's my fault -- sorry Albert, I didn't mean to hijack your thread.

Can you tell us what discs you used (Gehmann?) in your experiments? And were the tests conducted indoors or outside? I'm wondering if in variable light conditions -- such as on a cloudy day -- if there is a good compromise colour for the disc?

Jason
Albert B

To make things clear...

Post by Albert B »

I am NOT talking about the color if the filters inside the iris, But talking about the color of the disk that (normally is black colred) and contains the peephole you aim through (the metal disk).

Many years ago whwn the orange-brown irisses where introduced I used a can of carpaint to coler mine a kind of reddisch/orange. It always worked better than a black disk, was more restfull to my eyes because they received more light and made the iris of my aiming eye smaller, making the sight picture sharper forcus.

Recently I started using cardboard disks with a small hole in the middle colored with water paint (my daughters) in the colores: skyblue, dark green, light green, orange, red. The disks were (one at a time) pasted to the rear of the metal iris disk.
Both indoors and outdoors I got the impression that using a blue disk was far more restfull to my eyes and that my eyes were 'drawn' to the center of tehe disk, while using a red or orange disk the eyes were 'drawn' to the outside to the bright color. This felt very irritating.
My club has an outdoor 50m shooting range, and in wintertime it is dark and only the target and the shooting points are lit. That means while aiming we are looking through the sights, seeing only a sharp lit target, a lot of black emptyness around it and a dim lit surrounding of the rear sight. This situation causes very much scattering of light in the eye as the iris of the opens up because of the low light level entering the eye.

The cones in the eye work only with good light levels, showing color. The rods are then saturated. At low light levels (the situation on our and many other shooting ranges) the rods take over but they are most sensitive to light in the blue spectrum. That means that you get the most light reflected from the iris disk into your aiming eye when the disk is blue colored. Any other color would not have any effect on the rods.

Las night a fellow shooter offered assistance shooting several series prone, each with another color cardboard disk attached to the rear of his rear sight. This was the result:
Red/orange: POI between shots varied the most, als the centerpoint of the groups changed constantly (he stayed in position, I did the changing of the targets on the target carrier).
Light green: shots were closer together, cnter of POI changed less
Dark Green: even better
Blue: the center of the POI remained at the same place, the POI of all 2-shot groups was very close together, the 2 shotholes often touching or overlapping. He made the comment that his focus/aim picture was brighter and remaining much longer sharp while aiming.
He too is now searching for a way to color his iris disk.

So far the results in a nut shell.
It would be helpfull if others would repeat the experiment and report their findings.

Good shooting and thanks,
Albert B
(The Netherlands)
peepsight
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Post by peepsight »

Albert

One things for sure, a black iris disc is going to reflect the least light back to your eye. The eye needs light and lots of it. The light that the eye sees through the peep hole which on average is about 1.1-mm is not sufficient which is why peripheral light entering the eye is important. Without this peripheral light, eye strain can start to affect your sight picture.

Although as you say the light colour spectrum [blue] has some benefit, its the amount of light entering the eye that is important.

Although blue works for you, i suspect that other colours may work for other people.

I only shoot air rifle on an indoor range with artificial light but i have a set of Gehmann coloured discs.
My old AHG rear iris is a matt orange and so far has worked for me but i will try the blue next time and report back.

Thanks for an interesting subject

Peeps
Albert B

From what I have learned...

Post by Albert B »

from the internet the 3 types of cones (red, green and blue sensitve) are most sensitve to red and green light - the blue sensitve cones needing a higher light intensity.
But now the question: why do we need more light reflected into the aiming eye if the light intensity is good (daytime / open range / well lit indoor shooting stand etc.) by using a reddish iris disk that only works with cones that are working with good or high light levels?
It is my opinion that we need the most reflected light when lighting conditions are bad (low light levels). In that situation the reddish color is useless because the cones do not register properly in that color and light level, and the rods take over; and they opperate on the blue side of the light spectrum.
Other colors of the iris disk may be helpfull but only in special situations like:
sunsett producing reddish light that can be neutralised by perhaps a greenish iris disk; or greenish light caused by green surroundings (walls/bushes/trees) beeing compensated by a reddish color.

The catalogs mentioned in an earlier reply are not specific. The only mention that : "outer rings change the light colour at the eye" - that is something we all know.

I am looking forward to the outcome of your experiments.

Thanks,
Albert B
(The Netherlands)
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Jason
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Post by Jason »

I recently purchased a new Gehmann rear iris with the coloured rings and I have a 50 metre match tomorrow. The weather will be clear and sunny and the range faces north, so the lighting conditions should be ideal.

The only variables I'm really worried about are my prescription (currently under review) and the fact that I am quite badly red/green colour blind. But I'll let you know how it goes.

Jason
peepsight
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Post by peepsight »

Albert
Sorry its been so long, but i found Blue was good for me on the indoor air range under artificial light. Black seemed to have no advantage and white was a disadvantage. These colours may not suit every one so i say experiment your self to find a coloured disc that works for you.

Peeps
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Jason
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Post by Jason »

I tried blue and green rings and the standard silver/blue on the iris itself and . . . wait for it . . . I noticed no difference. I am colour blind and I did forget my shooting glasses (don't ask) but I found that the shade produced by my visor countered any obvious benefits of the coloured disc.

I was shooting prone, and during the first relay, the sun was shining on us from about 2 o'clock and the entire line was in the sun. By the second relay only the front of our barrels were in the sun, and then by the third we were completely in shade.

I asked another shooter on the line using a blue disc if he had noticed anything different and he said that he hadn't made up his mind yet.

I will keep experimenting, however, and let you know what I find out.

Jason
Albert B

my findings

Post by Albert B »

Peepsight and Jason,
I have been shooting a blue iris for some time now. My findings so far are:
During outdoor shooting with enough surrounding light the only advantage of the blue iris is that my sightpicture stays sharp for a longer period of time and contrast between light and dark surfaces stays moderate. (the picture does not 'haze' as fast as with other colors like orange and green. The picture looks "cooler").
When using it indoors and beeing positioned on a dark shooting point with brightly lit target, the sight picture stays clear and does not blur.
I have the feeling that my eyes do not fatique as fast with the blue iris, compared to other or no colors.

Albert B.
peepsight
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Post by peepsight »

Hi Albert

Its an interesting subject and i suspect that different colours may well suit different people both for out doors and in doors.

My old AHG iris has a rear disc that is a matt dull orange and seems to work just as well as the blue disc in doors.
What's important is that the aiming eye needs some peripheral light input from around the firing point and discs that are just matt black hinder this.
Other colours such as blue may well enhance light to the eye.
Peeps
tsokasn
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Post by tsokasn »

What's the best/prefered way to paint the iris plate without destroying the iris?
peepsight
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Post by peepsight »

I would not recommend painting the iris disc, just try on the various coloured snap on caps and see what suits you.

Peeps
Albert B

paint

Post by Albert B »

I used a spraycan of blue dull carpaint to color my iris disc. As long as it does not cause a glare it should work.

Hard to describe: i covered everything that does not need color by tape. To cover the irisopening (1.1mm) i made a paper cone from a strip of paper and stuck the point in the opening before spraying the paint.
(Here in the netherlands kids use a pvc electrical cable pipe of 1/2"diam., as a blowpipe and take strips of paper and fold paper darts or arrows in the shape of a slender cone to blow them out of the pipe - I am 52 but had a lot of fun with it when i was a young kid. Don't know the english name for it, but i hope you know what i mean).

Albert B
tsokasn
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Post by tsokasn »

Peepsight
I have Gehman's interchangable colour rings but they leave quite a lot of black area on the iris disc
Albert B
I see your point.
peepsight
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Post by peepsight »

I have seen some shooters paint this black area with 'Tip-ex' as it is a Mart white Finnish and can be scraped off easily if you don't like it.
Scrape off with a wooden tooth pick so you don't scratch the disc.
Be careful that you get no dirt and paint debris in the iris peep sight.

Peeps
sting
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Placement of the Rear Sight

Post by sting »

I was wondering if you have tryed moving the Rear Sight away from the eye ? I think you might see that the sharpness would stay longer.
How far do you have the eye to the Rear Sight ?
Ken
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