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Prism

Posted: Wed Sep 14, 2016 1:54 am
by Modena
Hi, has anyone used or do use a prism to swap the sight picture to the "other" eye, as per the MEC swap

I am left handed but right-eye dominant, wondering what people's experiences are of devices like these;

Image

in a related aspect, I noted some people in ISSF/Olympic finals shooting without any form of blinder, what/why would warrant this? Is it a personal thing? I wonder if I was aiming with my dominant eye I would not need a blinder.....

Re: Prism

Posted: Wed Sep 14, 2016 3:15 am
by TenMetrePeter
Re the second point IF you can shoot with both eyes open and unblinded there are big advantages with balance, and eyes working together etc.
I simply can't do it so I use blinders.

Re: Prism

Posted: Wed Sep 14, 2016 4:40 am
by Modena
TenMetrePeter wrote:Re the second point IF you can shoot with both eyes open and unblinded there are big advantages with balance, and eyes working together etc.
I simply can't do it so I use blinders.
yes that is interesting, although it occurred to me that with the prism your non-aiming eye would be staring at the chassis of the prism, which would act like a black blinder I guess.

Re: Prism

Posted: Wed Sep 14, 2016 6:54 am
by Tim S
Modena,

I know of a few shooters who have used periscope-adaptors to shoot L-eyed and R-shouldered. Most have complained about a very dark sight picture. I have noticed more shooters using the out-rigger devices that simply shift both rearsight and foresight over to the left eye. All who use periscopes and outriggers do so because the vision in their right eye was too poor to aim. I know many more cross-dominant shooters who mask off their dominant eye (anecdotally a solid black blinder is best) and shoot right-eye and right shoulder (or vice versa).

For smallbore, the big advantage of not needing a blinder on the non-aiming eye, is being able to see more wind flags.

Re: Prism

Posted: Wed Sep 14, 2016 7:00 am
by Modena
Tim S wrote:Modena,

I know of a few shooters who have used periscope-adaptors to shoot L-eyed and R-shouldered. Most have complained about a very dark sight picture. I have noticed more shooters using the out-rigger devices that simply shift both rearsight and foresight over to the left eye. All who use periscopes and outriggers do so because the vision in their right eye was too poor to aim. I know many more cross-dominant shooters who mask off their dominant eye (anecdotally a solid black blinder is best) and shoot right-eye and right shoulder (or vice versa).

For smallbore, the big advantage of not needing a blinder on the non-aiming eye, is being able to see more wind flags.
The outrigger is interesting to me too, and makes me sort of wonder why the periscope exists, at many many times the cost of an outrigger, why bother with the periscope? Are the outriggers ISSF legal?

Re: Prism

Posted: Wed Sep 14, 2016 7:32 am
by Tim S
Modena wrote: The outrigger is interesting to me too, and makes me sort of wonder why the periscope exists, at many many times the cost of an outrigger, why bother with the periscope? Are the outriggers ISSF legal?
I believe that periscopes are less fiddly to set up than outriggers, as the outrigger completely changes the zero. I think the periscope is also less sensitive to knocks. I've never heard that outriggers are not ISSF legal; perhaps David Levene can comment (hint, hint!)?

Re: Prism

Posted: Wed Sep 14, 2016 9:23 am
by David Levene
Tim S wrote:I've never heard that outriggers are not ISSF legal; perhaps David Levene can comment (hint, hint!)?
Nothing in the ISSF rules about outriggers apart from 300m Standard Rifle and Air Rifle where they are allowed for cross-eyed shooting under rule 7.4.4.1c:-
"Distance from center of the front sight ring or top of post to center of bore either directly above or offset (except for those athletes firing from the right shoulder but using their left eye)."

For the other rifle events, if they support normal non-lens (at the moment) sights then I can see no problem.

Prism sights are slightly different because of their optical properties. They are allowed however for cross-eyed shooting under rule 7.4.1.6f:-
"A prism or mirror device may be used when shooting from the right shoulder while aiming with the left eye, providing it does not have a magnifying lens or lenses. It must not be used when shooting from the right shoulder when using the right eye."

6.1.2f obviously also applies:-
"When a Rule refers to right-handed athletes, the reverse of that Rule applies to left-handed athletes...."

Re: Prism

Posted: Wed Sep 14, 2016 4:59 pm
by bugman1955
I tried one a few years back. I found I could not get close enough to the rear iris, my eye relief was too far away. This was caused by the angle of the prism for the right eye (trying to shoot with my left eye) My glass lens touched it.