TargetTalk

What happens when you put a colored lens between your eye and the sights ? Lets take a look at what happens with a camera. As soon as you put a filter of any color over your camera lens you find that you must open the F-stop or slow the shutter speed. When you do either you sacrifice depth of field to compensate. How does the reduced depth of field relate to sight allignment ? You must be able to see both the front and rear sight clearly in order to properly align the two. Are you williing to sacrifice a certian amount of depth of field in order to use a colored lens ? I examined this issue and decided that I was unwilling to make the trade off. I only shoot with clear lens, no matter the light conditions. Am I correct ? Good Shooting Bill Horton

Coloured filters will reduce the amount of light transmission to the eye thus you may have to open up the rear sight iris a tad to compensate.

Certain colours do enhance the sight picture contrast [on indoor ranges] which in its self may over come the slight deficiency of a slightly wider iris aperture.

Reading the book 'Air Rifle Shooting' they don't seem to be fully convinced about using coloured filters on indoor ranges with artificial light.
I tried filters for a while but found they did not help. There are some shooters who prefer them. Its a very individual thing as no two people are the same.
Peepsight

When shooting from under a firing line cover to a sunlit target, I find that I must do something to not have my eye drawn to the brighter target.

I would think coloured filters on an out door range with the target lit by day light would be very useful. Try it and see is the best policy.
Peepsight

Outdoors and covered, I discovered completely by accident that my non prescription "Ray-Ban Wayfarers" provided an incredible sight picture. No more glare and ghosting from the (reflecting) target. Front sight absolutely clear, sub-six hold outlined with clear, sharp bands of white.

Now... The Ray-Bans are not what I want to shoot with day-in and day-out. But the extremely dark, grey lenses are perfect. Wish I could find out what lens it is, and get some made in a more appropriate style.

Anonymous wrote:Outdoors and covered, I discovered completely by accident that my non prescription "Ray-Ban Wayfarers" provided an incredible sight picture. No more glare and ghosting from the (reflecting) target. Front sight absolutely clear, sub-six hold outlined with clear, sharp bands of white.

Now... The Ray-Bans are not what I want to shoot with day-in and day-out. But the extremely dark, grey lenses are perfect. Wish I could find out what lens it is, and get some made in a more appropriate style.

I have been very happy with the lenses I have purchased from Neal Steppe at ISS. If you send your Raybans to him, he might be able to get the optician he uses to duplicate the color in a lens for shooting glasses.

You are aware that any lens be it clear or coloured reduces the amount of light reaching your eye.

We need an optometrist on this one - any takers?

This subject is more involved than if the eye were a simple camera. The brain interprets the image that is projected onto the retina. What gets onto the retina follows optical laws, but how the brain works is something we are only scratching around beginning to understand.

I don't profess expert knowledge, but I do know that perceived sharpness and perceived contrast are not the same thing. Sure, decreasing the light into the eye causes the pupil to open. This decreases depth of focus and increases all sorts of other aberrations built into your particular eye. But if the light input and pupillary dilatation are due to something that improves perception in some way, for example sunglasses, the nett benefit might considerably outweigh the small degradation due to a slightly bigger pupil.

One optical aberration is chromatic aberration. Different colours will focus on different focal planes. I'd guess that this gets worse (as most things do!) with age. Camera lenses are made to be as free from this as possible - the eye is not. Sticking a coloured filter in front of the eye allows nearer to monochromatic working, so you can knock out one aberration and improve perception in some circumstances (perhaps).

Does your optometrist get you to look at red and green targets? This uses the eye's chromatic aberration to advantage. When we age, we lose our ability to change our eyes' focus (accommodation) and the process also becomes much slower. This can cause problems at the optometrist, because you tend to use your residual accommodation to try to make the silly letters clearer - you accommodate. Then the optometrist changes the lens, but your stupid, old eye is stuck with the focus it has just achieved, and only slowly recovers for another attempt at focussing. You don't really know whether it's the optometrist's lens or your eye that makes things look better or worse.

As I understand it, to get around this residual accommodation problem, optometrists use a lens that deliberately makes the target blurred. No amount of attempted accommodation can help, so your eye gives up. The background is changed from red to green, and the optometrist asks you which looks better. You are really being asked which has the greater contrast, because they both look fuzzy. Accommodation is knocked out, but because green light focusses in a different plane to red light, it's equivalent to changing the lens in front of your eye a little bit. These red / green judgements are, I find, difficult and confusing, but my optometrist says I get consistent answers and can distinguish 1/4 diopter changes. Pity you can't get lenses reliably made so accurately!

Does this explain why things ain't so simple? Perhaps you might try coloured filters for contrast-enhancement. And if you ever wear sunglasses, you already do it! Perhaps it won't work for you, but, like we have been told ad infinitum, if it works for you, do it!

Here is the site for Dr. Norman Wong, likely the most knowledgeable Optometrist around for shooters.

http://www.starreloaders.com/edhall/nwo ... l#eyeguide

That being said, any filter except red will give the perception of a sharper image of the sights (or anything else for that matter).

How many times have you heard a shooter using chrome yellow "shooting glasses" say that the yellow caused the scene to be "brighter"?

Obviously, any lens in front of the eye absorbs some light so the amount of light reaching the eye is reduced. The "brighter" effect is due to filtration of the almost UV/blue component of the light and gives the "appearance" of brightness due to the crisper image falling on the retina.

I strongly suggest that anyone on this forum having an interest in the optics of shooting see Dr. Wong's site shown above. He is a trained professional and a Master pistol marksman and know whereby he writes.

On a personal note, the front page of the above site has a photo of the "ClearsighT" device that I invented and marketed in the early '80s. Sadly, I lost my loupe supplier and it is no longer available. Almost every bullseye shooter from the "Old days" I meet has one of the ClearsighTs in the gun-box.

Tillman

JackH:

Some shooters use an adjustable iris to control the amount of light hitting the eye, and additional positive diopters to control focal plane.

e.g., Brightly lit target outdoors: stop the iris down and apply + diopters.

Oddly enough the same technique is used regardless of how much total light is available . . . it is the ratio of target vs. ambient light that determines the utility of various iris/diopter settings.

Refering to the comment about any glass reducing the amount of light reaching the eye, Let me please add that your eyes are too precious to risk shooting without protection and a good pair of shooting glasses are essential to protecting the eyes. Good Shooting Bill Horton

Bill I was not suggesting not to use lens, was just pointing out the fact that all lenses , not just colored ones as were suggested in your post, reduce the light hitting the eye.