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Lens

Posted: Mon Apr 17, 2017 7:14 pm
by Martin Catley
I am currently using a lens on my rear sight using an Anschutz fitting. When shooting, mainly indoors my efforts are extremely varied. I must say that I am currently having aditional probems with Cataracts.

After looking at different ideas I am wondering if the lens I have been using ( seem to be getting the picture I need) could be giving me variations as it is un-coated.

Any comments on coated and un-coated especially when used with artifical lighting?

Re: Lens

Posted: Mon Apr 17, 2017 11:53 pm
by ShootingSight
It will make some difference, but not a lot. Plastic is an excellent optical material, and typically only loses 1-2% of visible light as it passes through. Coating can reduce that to 0.5%. So the extra 1.5% light will make the image slightly brighter, and a little more contrasty, which is important if you have cateracts, but I don't think it is enough to be driving a marked performance shift.

Be sure you use a lens that has 0.50 diopters added to your distance prescription for a rifle. This will shift your eye's relaxed focal point to the hyperfocal distance of the front sight.

Art Neergaard
ShootingSight llc

Re: Lens

Posted: Tue Apr 18, 2017 9:29 am
by gwsb
Here is my 2 cents from a life time of trying to shoot with bad eyes.

Check with your Dr about having the cataracts fixed. If you can't see clearly you can't shoot.
If you mostly do indoor shooting I highly recommend you try hard contact lenses. Hard lenses remove a multitude of potential vision problems for shooters, and have only one downside. The downside is the issue of wind drying out your eye and blowing dust into it. Both can be very painful with hard lenses. Indoors that shouldn't be a problem.

The upside is that hard lenses provide better visual acuity. Unlike soft lenses, which are basically a conventional lens directly on your eyeball, actually remove the vision problems. This is especially great if you have astigmatism. When I could wear hard lenses they took my vision from 20/zillion to 20/12. I was actually able to see the bullet holes at 50 yd.

Good luck with whatever you choose.

Re: Lens

Posted: Wed Apr 19, 2017 2:01 pm
by TenMetrePeter
I have a deteriorating right eye lens and get entoptic images of my retina veins using rifle sight. Any eye defects will be magnified with a small sight iris hole . Try a variable iris size nearer 2 than 1mm. I know this doesnt answer your actual question but its another thing to try.

Re: Lens

Posted: Wed Apr 19, 2017 2:40 pm
by Martin Catley
Thanks for all the replies you have given me a lot to digest.

What I was partly looking for was would an un-coated lens in difficult lighting conditions give "reflections" which might cause variations of sighting?
Should you use a non reflective one especially indoors?

Re: Lens

Posted: Wed Apr 19, 2017 3:42 pm
by Martin H
Hi Martin
I find an uncoated lens gives less contrast. I notice the sight picture looks "dull" if I use an uncoated lens.
For non-ISSF indoor shooting I ensure I use side blinders to minimise the reflections from light behind me.
Cheers
Martin