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Discussion Starter · #1 ·
I have made some target shooting adjustable iris safety glasses.

Such devices are sometimes used for target shooting disciplines that require iron sights because they offer several advantages:
  • Superior depth of field
    • Both the fork tip and your target will be in sharp focus at the same time
    • Your eye will not have to find focus
    • Superior focus with or without spectacles
  • Lower lighting levels
    • Less eye strain in bright light
    • Your iris sphincter and dilator muscles have less work to do
    • Your ciliary muscles around the lens have less work to do
  • No cross-dominance issues
    • Only one eye can see
    • If like me, your left eye is ordinarily dominant and draw the pouch under your right eye, it will avoid parallax
    • No need to squint
These glasses look all gucci, but they cost me all of $10 in parts and the prohect was done in 20 minutes. You could make a passable non-adjustable in five minutes from a $3 pair of safety specs, a small drill and some black spray paint. A better, though still non-adjustable, version would use a bit of soft drink can with a pin-hole drilled in it to make a better, thinner, aperture plate.

They are functionally similar to Knobloch shooting glasses with an adjustable iris and left eye blinder, except for the additional benefits of:
  • Eye protection
  • Greater range of iris adjustment
  • More complete black out
  • All matt-black internal surfaces to cut reflection from the face
Drawbacks:
  • Restricted vision
  • Loss of binocular vision and depth perception
  • Reduced light transmission
  • A bit Borg-tastic; other shooters will likely take the ****
But don't knock it till you've tried it. It makes a huge difference in vision.

Fully Stopped Down to 0.7mm for Daylight Shooting



Partly Stopped Down to 2.5mm for Indoor Shooting



Fully Open



Specifications:
  • 2mm polycarbonate safety glasses
  • 10 blade aperture diaphragm, round aperture at all settings
  • Continuously variable from 0.7mm to 11mm
  • Eye relief approx 20mm
  • AoV at 11mm = 300 mils (17 degrees)
  • AoV at 11mm = 180 mils (10 degrees)
 

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Member, Brotherhood of Slingshot Nutz
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Dan,
Thanks for that. I did happen to visit my ophthalmologist the other day. I have been shooting indoors because of the neighbors and cops, but that's another story. He said I should try increasing the lighting. So for the last couple of days I have been shooting with a shielded light aimed on the target. So far so good. Another problem is that I have to hold in my right hand even though my right eye is dominant, which is why I always shoot with both eyes open. I'm not shooting that much better now but I can see the target a lot better and my eyes haven't done any dancing.

BTW, another interesting thing is that when I shoot with my non-prescription safety glasses, I shoot better than I do wearing my prescription glasses. I chalk that up to just being "zeroed" that way through habit?

Thanks again, Dan, for your thoughts on this problem. If my eyes start dancing again, I will try experimenting in the vein you suggested.
 

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Discussion Starter · #3 ·
Bill, if you send me a pair of safety specs with the correct hole centre marked on with a marker pen, I will send it back with an aperture disc and black coating.
 

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Neat idea.... I wanted to know the same thing.... How do you adjust the iris?

-Restita
 

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Discussion Starter · #7 ·
Neat idea.... I wanted to know the same thing.... How do you adjust the iris?

-Restita
In the photos, there is a silver metal bar sticking out of the iris housing. Twiddle that up and down.
 

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HOBBYIST-SOPHOMORIC-JACKA$$
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i used to mess around with one of these auto darkening welding helmets...

 

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"Mighty Can Smiter"
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Z- that is cool idea and design... it might be a bit over kill for many IMO only due to the draw backs that you have already mentioned.

The key point one wants to reach is to reduce glare when shooting outside.. with your design the fully open iris would probably be sufficient if one fines the need for more help.

Focusing of the eye will still occur the same way since the fork focus vs the target focus will remain. Also a blackened non dominant eye would only assist in extreme light conditions where closing it would not be sufficient.. and in that case it will not change the light condition past the fork for the dominant eye either way.

Below is my set up, when I wear glasses (while not making videos since I fidget alot
) I shoot with both eyes open so I really don't want my non dominant eye to have no view ahead of me, but I do want my primary focus to be pin pointed to my dominant eye... So with a lens change of a clear lens for dominant and a grey lens for non-dominent will provide me with enough glare protection without hindering my viewing capabilities while I am not drawing to shoot. Also forces my focus to my dominant eye.



Again I do see how your design can serve a purpose for some,, and it is an excellent idea... I am just sharing what has been beneficial for me.

Cheers

LGD
 

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Imperial, it's not like a pair of sunglasses that reacts to light. It improves vision, particularly depth of field.

Here are some (simulated) examples.

Without Target Glasses, Eyes Focus on Fork



The fork is in focus, but the target is out of focus.

Without Target Glasses, Eyes Focus on Target



This is how people shoot. The target is in focus, but the fork is out of focus, especially in low light when your pupils dilate.

With Target Glasses, Stopped Down to Ideal Setting



You can see the target and the fork are both in focus, facilitating correct aim. The target is in better focus than without the artificial iris. The overall lighting level is corrected as well.

With Target Glasses, Stopped Down Far Too Much



If you go too far, the image becomes vignetted and occluded and the light transmission is reduced too much. Different lighting conditions require different settings, so it's best to have a range of adjustment.
 

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Discussion Starter · #11 ·
I find this makes a lot of difference to me because of my cross dominance and weaker right eye.

A further refinement is to add polarisers or colour filters to improve contrast. This is not necessary when shooting a black on white target.
 

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Discussion Starter · #14 ·
Interesting,, I really didn't see the possibilities of this... seems plausible.

LGD
Trust me, I'm using it and it works. The theory is sound and it's widely used in other shooting disciplines. Just about any time people get really serious about hitting a target with a weapon that has a sight but no glass optics, you'll find this technology. It's not controversial and I don't think anyone'd ban it from competition, with the possible exception of the Belgians.

This link below is an example from the air-rifle community. It describes the optical effects.

http://www.pilkguns.com/varga.shtml
 

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I have a problem in that I hold my slingshot in my right hand and aim with my right eye. I have solved the problem by using peep-hole glasses. But because of the right hand - right eye problem I have to use peep-holes for both eyes. I have written about it extensively at my web site.

http://www.SuperShooting.com/Sights.html

Jack Koehler
 

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Hey there, ZDP ... wasn't trying to distract from your suggestion, or your inventiveness ... your hand made one looks very professional, and I applaud you for bringing this to our attention. Once I started looking around for irises, I found the commercial ones made for shooters and thought I would pass along the information. And of course for those with more time than money, I thought making your own adjustable iris might be a fun project. For high precision shooting, I think one of these gizmos would be the ticket! Of course Bill Hays had one installed at birth!


Cheers .... Charles
 

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That looks very interesting. I know some guys who used that sort of thing for target shooting with pistols... It probably would work well with a slingshot as well. One of these days I might like to give it a try!
 

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For high precision shooting, I think one of these gizmos would be the ticket! Of course Bill Hays had one installed at birth!


Cheers .... Charles
You know something Charles... you might actually have a point there that I hadn't thought about much before... I had to wear an eyepatch on my left eye for about 6 months when I was a kid, due to a hook in the eye.... and that might have helped out the whole target overlay ability I find so easy that it seems so many others have a problem with...
 

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Philly
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Bill, I have used the old Merrit adjustable eyeglass attachment for iron sight pistol shooting for years, works great and can be put on a pair of prescription or safety glasses via the small suction cup. I like the glasses, cool idea, Thanks for continually making improvements to the art of slingshot shooting, I and many others have learned a lot from your tutorials and videos.
Philly
 
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