Diopter for air rifle front sight

[moonlightrun]

To assist shooters who could use vision help companies make "Diopters" to attach to front globe sights on air rifles. For example, Champions Choice offers 18mm and 22mm Diopters in the following powers: .25+, .50+, and .75+.

Does anyone know where I might find Diopters in additional powers such as 1.00+, thru 2.00+?

[BigAl]

I think the highest power Eagle Eye lens is the 0.75. These devices are not legal under ISSF for ANY rifle shooting event. The ISSF do not even allow the use of a vision correcting prescription lens to be mounted on the rearsight. Any vision correcting lens in ISSF competition has to be worn by the competitor as either glasses or contacts. Eagle Eye type lenses, where they are allowed under domestic rules, are usually limited in power. This is because when used with a matching lens in the rearsight they effectively become a Galilean telescope. At that point they (should) stop being an aperture sight, and become classed under any sights.

Alan

[moonlightrun]

Alan, All of the rules aside, I'm trying to figure out how to maximize my vision. The Eagle Eye 0.75 does a pretty nice job but the target (although bigger) is not clear. I was wondering if I was able to find perhaps a 1.00+ or 1.25+ diopter maybe I could get the best of all worlds. Any ideas would be appreciated. Bob

[BigAl]

Unfortunately if they are not legal to use, there is going to be no market for them, so no one is going to manufacture them. Maybe you could get a local optician to grind you a +1 or +1.25 Diopter lens of a suitable diameter for you foresight tunnel, that is likely to be your best chance otherwise.

Alan

[Tim S]

Also, an eagle eye doesn't really change the focus of the target anyway, as it's too far from the eye. It just makes it larger. To get a good sight picture, i.e. a sharp foresight and a distinct target, see an optician about a prescription lens to wear in glasses.

[moonlightrun]

Thanks for the info. The .075 did make the target larger and therefore a just a tad clearer. So far I've been unable to find an optometrist who is interested. There is something called a Microsight that is supposed to make the front sight and target clear but I hesitate to experiment with the purchase because they are over $100 and don't actually fit my rifles.

[Tim S]

The microsight is a Fresnal Zone Plate, a lens that's not technically a lens. If you search on this forum, there are reviews/comments. From memory the microsight makes the sight picture very sensitive to eye relief, and somewhat dark.

Making a shooting lens should not be that difficult, so I'm surpised you can't find someone willing to make one. In most cases it's your normal distance prescription (including cylindrical correction) + 0.50 to focus the eye ahead of the foresight.

[moonlightrun]

I'm on the way to Sams right now. They have an optical dept. I will try them. Using the info. you gave and the fact that my current diopter is 0.75+ I will ask them if they can make a lens for my shooting eye which is 20/20 and add a 0.75+ to a lens. If that idea would work maybe I can find a pair a cheep reading glasses to test first.

[BigAl]

I see from your comments that you are trying to get a setup where both the foresight and target are in sharp focus. Unfortunately that is actually optically impossible. All you can do is get set up so that the foresight is sharp, the added depth of focus from the rearsight aperture coupled with a lens that will naturally focus your eye just a little in front of the foresight is the best you can do. You just have to accept that the aiming mark is a little (or even quite a lot) fuzzy. Our rifle sights are actually set up to use an area aim, so the fuzziness is not actually a bit issue with regards to accuracy of the shot.

The only way to have both a sharp aiming mark and a sharp sighting element is to use an optical sight. Telescopic sights allow the aiming mark and the reticule to both be sharp due to the fact that the sight focuses a virtual image of the aiming mark (target) on the same location as the reticule. The eyepiece optics then provide an image that eye can focus on. The telescopic sight then effectively uses the eye itself as the rearsight in the system. It does this by relying on the shooter placing the eye in the correct location in relation to the scope optics each time. failure to do this correctly will result in parallax errors.

Actually failure to correctly place the eye in relation to the sights when shooting with aperture sights will also cause parallax errors, which can result in some really bad shots. Often shooting an uncalled 8 or 9 is simply down to miss alignment of the eye with the rear aperture.

Alan

[moonlightrun]

Thanks Alan. Once again we want the impossible. I put together a fiber optic front sight that I added a light to. Because of the light, the little green dot is always clear. Now, if I can just get the target to clear . . .

[nglitz]

Take a look at http://www.shootingsight.com/ especially the tech articles.

[moonlightrun]

I'll check the site and articles out. Thanks

[moonlightrun]

Norm, The info. and articles were very helpful. Thanks.