ajustable iris question

[bubba_zenetti]

I just got a Gehmann clip on iris thingy. I was wondering what the proper setting for the iris size would be? Is it a matter of personal preference or should I be setting to for a specific sighting picture against the target?

[RobStubbs]

What did you get the iris for ? What I mean by that is you bought it for a reason so that should dictate how you set it up. When I used one I had it set fairly wide open but the smaller it is the greater the depth of field. A big depth of field allows sights and targets to be in focus at the same time but that is counter productive. It encourages you to look at the wrong thing i.e. the target rather than where you should be looking, the sights.

I threw mine away as advised by my coach but I know quite a lot of people still use them.

Rob.

[David Levene]

I threw mine away as advised by my coach but I know quite a lot of people still use them.

I wouldn't have thrown it away Rob. They can be quite useful, provided that they are set with an aperture big enough that it doesn't affect the sight picture, for ensuring that you have a consistent head position.

I agree though with your comments that a greater depth of field can be counter productive.

[Fred Mannis]

They can be quite useful, provided that they are set with an aperture big enough that it doesn't affect the sight picture, for ensuring that you have a consistent head position.

I find it helpful to use an iris set at ~5 mm diam. Sufficient to help me keep my head in position, and my eye in line with the optical center of the lens, but not small enough to increase depth of field or darken the image.

If you search the Pistol forum with keyword 'iris' you will find considerable discussion.

Fred

[CROB]

I too stopped using my iris because of depth of field distractions. However, I also found it harder to position my head/eye in the centre of the lense without it, and if you have an astigmatism corrected by your lense (as I do) that can be a problem.

I got around that by using the centering device for my Knoblocks. One of my home drills is maintaining position and developing a "feel" that I am in the right place and not moving. I do that drill with the centering device and it (so far) is helping me to keep my head position correct.

Don't use the iris to control the light outdoors. I use coloured filters for that.

[Weekend Shooter]

I started tinkering with a home made iris to see if it could make sense to invest in a real one.

aside from keeping my head in position, I was doing worse with it. I would have a front sight that was too clear and fine that would distract since the rear and front blade were clear. The result was that I would now consciously try to align and minimize my movements thus making the shot either go in well or fly off to a 6.

I figured that averages were in the long run better. So I went back to my usual graded glasses I use everyday to drive, work, live, etc.

Is my experience something on the correct path?

I'm a perennial beginner shooter though...

[funtoz]

Bubba -

And where were you Sunday morning while we were shooting Free Pistol, eh? We will be shooting informally tonight if you can drag your iris and self over to the the Kenmore range.

The iris can be used to help center the head by setting it fairly open. It can also be of benefit to those of us old farts that can't see a 50 meter target with our shooting glasses. Some of the younger guys don't understand that idea too well, having never had the experience of seeing nothing discernible in the washed out blur beyond the front sight. You tend to get more points if you actually shoot at your target. The trick is to get the aperture small enough to give good definition to the target without getting carried away and making that black thing too sharp. There is one other use for those of us that shoot outdoors in varying light conditions. Yesterday we started out in shade and by noon the sun had come over the trees and the intense sunlight made the targets flair. An aperture is able to cut a lot of that glare down to manageable levels without you having to buy a bucket of cool colored filters.

Larry

[deleted1]

I use the Iris on the Champions----the trick with the adjustment is to decrease the aperture of the iris until the target appears sharp then back off slightly and the front sight will stand out and become easier to focus on. I have also noticed in recent years when using the blinder---If the blinder is opaque or translucent ( I prefer the latter) I will use the blinder at about a 45 degree angle rather than all the way down---perhaps it is a peculiarity with my eyes---however, I find the ability to focus only on the front sight becomes easier than with the blinder fully down. Under certain lighting conditions (indoors) I do not use the blinder at all. Seems to work for me. I wonder if anyone else has tried this, and what are their results?

[bubba_zenetti]

Bubba -

And where were you Sunday morning while we were shooting Free Pistol, eh?

getting a speeding ticket on my motorcycle near umatilla. and yes the ride was worth the ticket ;)

btw, i am in the market for a free pistol if you know of one around for under $1000. i looked at the set over at wades and i thought they were a little beat up.

[hspepke]

Funtoz, where in Kenmore? I shoot in Issaquah, and in West Seattle.

[Nicole Hamilton]

Funtoz, where in Kenmore?

The club's formal name is the Wildlife Committee of Washington but the range is called Kenmore:

Kenmore Shooting Range
1031 228th SW
Bothell, WA 98021
425-481-8686
http://wcwinc.org

[hspepke]

Thank you, Nicole.