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diopter

Posted: Sat Feb 08, 2014 4:23 pm
by mitchellchandler_au
Hi all,
After a spell from fullbore i decided its about time to get back into it. I had a work place accident a few years ago and now have bugged up eyes and as a consequence need glasses to clear up the vison. I cant see a good sight picture like i could before the accident. I was after some reccomendations as to what rear sight diopter/aid i should consider.

Posted: Sat Feb 08, 2014 8:37 pm
by Josh Cox
Hello, welcome back.

There are a number of Optometrists that also shoot:

http://www.qldrifle.com/index.php/optometrist

Re: diopter

Posted: Sun Feb 09, 2014 3:10 pm
by NDO
mitchellchandler_au wrote:Hi all,
I was after some reccomendations as to what rear sight diopter/aid i should consider.



A good starting point for the rear lens that needs to be affixed to your rear sight is to deduct 0.25 dioptre from your normal distance script (keeping any adjustment you need for any astigmatism). This assumes you are using a 0.5 eagle eye up front. For example, if your distance script is -0.5/-0.75 Axis 75 then your rear lens would be -0.25/-0.75 Axis 75.

The intent is to keep the front ring in focus whilst sharpening up the aiming mark as much as possible. If the balance is not right, either the aiming mark or the front ring will be too fuzzy.

The lens can can housed in a prescription lens holder. eg http://sumosight.gostorego.com/accessories.html

Bryan Smith is an optometrist based in Queensland who understands shooters needs, he can make the lens for you to fit the Sumo presciption lens holder, or give you more detailed advice. He visits Sydney on a regular basis, not sure about other places.

http://www.qldrifle.com/index.php/optometrist

Posted: Tue Feb 11, 2014 7:15 pm
by mitchellchandler_au
Thanks for the reply guys

Posted: Thu Feb 13, 2014 8:27 am
by bsouthernau
You'll also find an adjustable iris on the rear peep a great help in keeping both the foresight and aiming mark as sharp as possible.

Barry

Posted: Thu Feb 13, 2014 9:53 am
by johnk
Though I haven't shot with a peep for a year or three, I used my normal corrective prescription, the master eye one adjusted by the ΒΌ dioptre necessary to clear the foresight, for both eyes set up in Champion shooting frames rather than carry a separate correction on the sight. There are several advantages:

    The lens is a constant distance from the eye, so corrective value doesn't alter. A lens on the sight can change value if you move your head to compensate for mound conditions.

    The cap protects the spectacles better in inclement weather.

    I was able to adjust the positioning of my off lens so I had better view of the surrounds (flags) with my head aligned with the sights.

    Looking through a single rear lens rather than my normal specs plus a clearing lens gave me a better outcome with available light, allowing the rear peep to be tighter.

Finally, I found that for senior eyes, polarised lenses remove refracted light rays & permit an even smaller rear aperture resulting in a deeper field of view & a better optical outcome.