TargetTalk

I have recently purchased a Hammerli 461 diopter sight and need help with Iris selection.My eyesight is shortsighted (Myopic) with my left eye -2.0 and right eye -2.25.I don't want to wear my prescription glasses or get shooting glasses if I can help it.

I am a left handed shooter who is left eye dominant.I have read that what works is a 1.5x magnification iris in the rear sight with no color or polarizing filters just magnification.

Is this true for myopia? What is the best setup rear or front sight magnification.

I usually use a scope but can't use this on my new target rifle .I want to use the diopter sight.

Also is Centra good or is there any mfg that is better.

Any input or help would be greatly appreciated.

It sounds like you are talking about a lens rather than an iris.

You cannot use a lens on the rifle under ISSF rules.

Centra make good irises. The other name to look out for is Gehmann. Anschutz irises are made by Centra.

If you are not shooting to ISSF rules than the combined iris/optic can work. It magnifies the sight picture, and you can alter the focus. Making the target larger would help for short-sightenedness.

Personally I think a single prescription lens, prescribed by an optician who understands the requirements for shooting (i.e. where the focal point needs to be), is a much better solution. The optic makes for a slightly dimmer picture, and is very difficult to clean. Also if you have an astigmatism, a prescription lens is the way to go - the 1.5x rearsight lens will not help here at all.

As for filters/polarisers, these can be useful if you are shooting outdoors in natural light. Filters are used to enhance the contrast between the target and the backing paper. Polarisers are useful to to down glare in bright light.

Foresight lenses again make the target (and sometimes the foresight as well, depending on where the lens is) larger. This can make it easier to see. Foresight lenses are not legal under ISSF rules, and cannot be used under UK NSRA rules with an adjustable rearsight lens (a single prescription lens is quite ok).

"If you are not shooting to ISSF rules than the combined iris/optic can work. It magnifies the sight picture, and you can alter the focus. Making the target larger would help for short-sightenedness. "

Ok thank you that's what I needed to know .I have no astigmatism so the 1.5x magnification should help.

"Foresight lenses again make the target (and sometimes the foresight as well, depending on where the lens is) larger. This can make it easier to see."

Using a .3 magnifier on my front sight would that help or hinder the target
picture. Used in conjunction with a magnified rear sight.

Bring into sharp focus.I understand there are tradeoffs.

Are you allowed two lenses (front sight & rear sight), or will having such be declared telescopic? I am not up to speed with rule changes, but have seen references where it is allowed and not allowed.

corning wrote:Are you allowed two lenses (front sight & rear sight), or will having such be declared telescopic? I am not up to speed with rule changes, but have seen references where it is allowed and not allowed.

Which rules?

David Levene wrote:

corning wrote:Are you allowed two lenses (front sight & rear sight), or will having such be declared telescopic? I am not up to speed with rule changes, but have seen references where it is allowed and not allowed.

Which rules?

US NRA International Rule book:

3.7 Sights
(a) Corrective lenses may not be attached to the firearm, in the rear sight, etc. Corrective glasses, and or filters, may be worn by the shooter.
(b) Any sight not containing lens or system of lenses is permitted. Light filters may be fitted to the front or rear sight, or both.
(c) Telescopic - Telescopes on rifles are prohibited.

NRA Smallbore rules appear to be different in that multiple lenses seem to be allowed asl long as there is no aiming reference.

corning wrote:

David Levene wrote:

corning wrote:Are you allowed two lenses (front sight & rear sight), or will having such be declared telescopic? I am not up to speed with rule changes, but have seen references where it is allowed and not allowed.

Which rules?

US NRA International Rule book:

3.7 Sights
(a) Corrective lenses may not be attached to the firearm, in the rear sight, etc. Corrective glasses, and or filters, may be worn by the shooter.
(b) Any sight not containing lens or system of lenses is permitted. Light filters may be fitted to the front or rear sight, or both.
(c) Telescopic - Telescopes on rifles are prohibited.

NRA Smallbore rules appear to be different in that multiple lenses seem to be allowed asl long as there is no aiming reference.

Maybe I should have asked "which rules are you shooting under?". That will provide the answer to your question.

David Levene wrote:
Maybe I should have asked "which rules are you shooting under?". That will provide the answer to your question.

I fear I may have created more confusion than help. You are absolutely correct. First question should have been: What country are you shooting in? The second question should have been: What rules are you planning on shooting under?

Even if you could use it, I would not recommend using the Gehmann or Centra rear magnifying iris. I am nearsighted also, I have have always gotten a better sight piccture with a prescription lens in my shooting glasses. If your shooting eye is a -2.00 you probably find that a lens of -1.50 or -1.25 works for you. Also, the glasses will protect your eyes. The iris won't. Mike Barron

You want an iris and a lens, as they do different things.

THe lens will drive where your relaxed focal point falls, and with a rifle, optimally you want +0.5 diopters added to your distance vision (without going into the optical math, this is the hyperfocal distance of the front sight of all rifles with a sight radius over about 27 inches). So if you are a -2.00 in your shooting eye, adding +0.50 suggests that what you want is a -1.50.

In addition, a small iris will increase the size of the depth of field which is centered around that ideal focal point. Either one alone will help, but ideally you want both.

With no astigmatism, I can make you a clip on lens that fits on your safety glasses, or I make adapters that can fit the lens in the rear sight (depending on what rules allow).

mobarron wrote:Even if you could use it, I would not recommend using the Gehmann or Centra rear magnifying iris. I am nearsighted also, I have always gotten a better sight picture with a prescription lens in my shooting glasses. If your shooting eye is a -2.00 you probably find that a lens of -1.50 or -1.25 works for you. Also, the glasses will protect your eyes. The iris won't. Mike Barron

I went and bought the Gehmann 575 Iris.
I shoot in the bright sunlight of the Nevada desert.
I have shot with my glasses & want to use the Diopter sight with iris.
Since my Anschutz has a rail on the very rear of the receiver which doesn't allow for much else.
A Diopter sight w/iris magnification is the best for me.

I'll try it for now and see the results if not I'll use my glasses or get the shooting inserts.

Thanks for all the input.

I too have a pre 1965 Anschutz target rifle. In my case a 1964 1411. Using it with a scope is no problem though, BKL make a mount that is perfect for the job. It is the One Piece 4" Reach Forwards, sorry but I don't have the model number to hand. I have used both my Sightron SII 36×42 and an Opti-Mate 36×44 (an almost direct copy of the Weaver T36) scopes in these mounts on this rifle.

Alan