correct iris position??URGENT!

[Basar Baypinar]

Hi everyone,

I wanna be sure that what is (must be) the "correct position" of iris? I'm using shooting glasses and iris also;and my iris not behind my eye and lens;on the out side of my lens..I've newly read some discussion which argue that "iris be used on the inside of the lens";must be locate between eye and lens ..Is it really true or what is your opinions about that?Am I doing really wrong and is this harmful to me?


Thanks a lot for your kind replies

Basar

[Guest]

Iris should go on inside (bettween eye and lens)

[Nicole Hamilton]

I'm confused. I'm not sure know why an answer to any question about using an iris is ??URGENT! Lots of even very experienced shooters never use an iris, so how urgent can this get? If you desperately need this information for your match in the World Cup finals this afternoon, wouldn't already have it? And if you're not at that level and not sure of the answer, couldn't you just experiment a little in practice to see if there's any way of using it that actually helps? What happens if you don't even bother with it at all? Is this the one remaining reason you don't shoot all 10's?

[deleted1]

Whether your iris is on front of the lens or behind the lens is a matter of a few millimetres----what is of most importance is that the iris be at centre of correction for your glasses. The tendency with the Merit or Gehmann irises is to place them in the wrong location on the lens as far as centre of correction. Most often they are placed in theupper left hand or right hand corner of the lens far from the c/oc. Additionally the Gehmann (anschutz) irises are large and the convexity of you r corrective lenses willl actually cause the iris to be tilted ( when viewed from the side) and this can cause distortion in you vision. The add some anastigmatism to the mix and it can be very tough to find a good adjustment---also when using too small an aperature you now introduce diffraction to the light----the iris is not an easy answer to everybody vision problems in shoooting.

[Fred Mannis]

My Varga and Knoblock irises are constructed such that in mounting the lens on the iris, the concave side of the lens must face the iris. Since the convex side of the lens must face out (toward the target), this means that the iris must be located between the lens and the eye. The use of this type of shooting glasses i.e. Varga, Knoblock, Champion, etc, means that the iris will always be centered over the optical center of the lens. As Bob Riegl points out, the use of a clip on iris is fraught with problems.

[Guest]

Whether your iris is on front of the lens or behind the lens is a matter of a few millimetres

Using a knoblock iris, there is 9 mm difference bettween mounting in front or behind.
Given the short distance anyway, this is a big percentage.

[ColinC]

I agree with Fred because the only position for the iris on my Varga shooting glasses is between the lens and the eye. The extreme curvature on the lens needed for my tired old eyes precludes the iris being put anywhere else.
Interestingly though, the Varga glasses came assembled with the iris out in front.
As for the iris, I have never used it in a match. I keep it wide open because when experimenting with it closed up, all it did was bring the target into clear focus which is something I do not need.

[Basar Baypinar]

Firstly thanks evert body for kind replies:)

Meanwhile, Dear Nicole; I'm a one and half year shooter and my approximately score is 545;max match score is 552. When I was starting to use shooting glasses (Knobloch), nobody could give any clear answer about to use it;even my coach too!!And I decided to use iris out of the lens, according to some pictures that I saw. I dont shoot since 4 months and I wanna turn back fastly again. And I wanna be sure that Am I doing some thinks right. When I saw the questions about iris using on targettalk, I send this message because I have never been really sure about effective using the glasses! URGENT because, I thinked that ıf I am wrong, I must not "loose the time"...May be I could get more 10's, but I couldn't..may be it would be a important reason (not main problem ofcourse)..

Sorry about my English;I hope I could tell my reasons:))) Am I right or wrong about my worries?Really I need yours kind feedbacks!!!

Best regards.

[stale]

I Your bag, far away from your shooting equipment.
Learn Your lesson to get front sight in focus, nothing else.
If You don't get focus on front sight go to an eye doctor.
Get correct glases with focus at approx 4-5 feet.
and by all means read the tread abowe.
"Tip to retain the front sight in focus", course that what's all about.
90% of shooters don't need the damn iris.
stale

[TargetTerror]

What is the benefit of having the iris on the inside of the lens (between the eye and the lens) versus on the outside?

Also, so long as you put the iris over the optical center of the lens, are there any other inherent problems with a clip-on irs (disregarding thing like fitment, as if you can getthe iris centered, there isn't really a fitment issue anymore)?

[PaulT]

The iris can be on either side of the lens, they are adjustable in diameter so this obviates any perceived advantage or disadvantage of either mounting location. Having the lens relatively close to the eye maintains a reasonable sized image for some shooters with stronger prescriptions for myopia (short-sightedness), therefore to compromise this positive advantage by attempting to place the iris in-between the eye and lens is not sensible.

More recent models that clip-on enable, as previously posted, attachment to the lens or the filter, both filter and iris being on the non-eye side of the lens!

That reminds me – a sales pitch….
For sale - sensibly priced Champion pistol adjustable diameter iris that attaches to the lens holder and is usually located on the eye side of the lens. Also have large yellow champion filter (excellent condition) also for sale. Please pm me as these are surplus to requirements (EU shipping preferred).