TargetTalk

Question for you "older" shooters,
At 57 years of age, I find with an enhanced prescription lens in my shooting glasses, I can get a very sharp focus on the front sight. However, the rear sight is not as sharp. Consequently, I end up with a narrow shot pattern in width, but elongated in the vertical, because the top edge of the front sight is obviously not aligned with the top of the back sight. What can I do to get both front and back sights sharp enough in my vision to get a clear alignment?
Elliott

Elliot,
You don't want both front and rear in focus - the front sight is the one that matters, the rear sight should be slightly fuzzy. A couple of suggestions though; try opening the rear sight wider that should help. One that I really don't recommend is to use an iris. It will give you a greater depth of field but IMO it will not help improve your shooting. Opinions are divided on the latter but I think it encourages bad technique and focus on the wrong bits.

Rob.

A Quibble On The Iris

I know Rob understands this, and many seasoned shooters would consider it a quibble, but (as Don Nygord points out in his "Notes") if you are using the iris to increase your depth of field you are using it wrong.

I hear newbies talk about the iris as if its purpose was to increase depth of field; when indeed, not only is that not it's purpose but is actually an undesirable side effect!

However (also as Don notes) the caution is entirely valid- as most shooters will fall into the "trap" of using the iris inappropriately.

So yes- if your intention is to misuse the iris, certainly don't get one.

If your intent is to control the amount of light entering the eye (to keep eye's natural iris a consistent size) OR if your intent is to use the iris as a way to maintain a consistent sight picture under varying light conditions, then the iris can be a useful tool. [Some say various filters (employed mainly by rifle shooters?) can accomplish the same thing as the iris but I don't know about that for pistol.]

For example- in a uniformly albeit dimly lit indoor range (think Canadian Grand Prix) I use the iris to eliminate the "corona effect" around the front sight and bring the front sight into deep focus. With my eyes, this would be impossible to do without the iris. (FWIW I use a fat front sight with liberal notch width)

So Elliot- an iris may or may not help (it helps me immensely) but the bottom line is:

Front Sight Crisp
Back Sight Slightly Fuzzy
Target An Amorphous Cloudy Blob

Steve Swartz

I totally agree with Steve. The iris serves the function he describes and saves wear and tear on the eye adjusting for light conditions.

The depth of field is a by-product of the iris, not the intent.

Tillman
Age 65, who just lost to a 75 y/o woman in an NRA match this weekend. She is a wonderful Master shooter and she uses iron sights!

It's all in the way you adjust the iris--I will gradually adjust the iris until the amount of light on the target suits my view and at that time my front sight will also be as sharp as it will ever be. There is not thought as to the rear sight just the target brightness and the front sight---the rear sight is lightly blurred---however all that being said, I had cataract surgery on both eyes three years back with lens implants and anastigmatic changes as well by lasering. This has rendered me with the brand new eyes of a teen ager or better, so the iris does also affect the rear sight sharpness to a point, in fact I can see the scoring rings on the Sports Pistol and ORF targets at 50 ft and 25 yards as well, with the iris. But once again I emphasize the fact that I adjust the iris for lighting without lifting the gun.

elliott wrote:Question for you "older" shooters,
At 57 years of age, I find with an enhanced prescription lens in my shooting glasses, I can get a very sharp focus on the front sight. However, the rear sight is not as sharp. Consequently, I end up with a narrow shot pattern in width, but elongated in the vertical, because the top edge of the front sight is obviously not aligned with the top of the back sight. What can I do to get both front and back sights sharp enough in my vision to get a clear alignment?
Elliott

If you can achieve proper horizontal alignment with a fuzzy rear ( as you imply in your note), then you can certainly achieve proper vertical alignment as well.

When I get vertical stringing, it is a sign that I am not paying enough attention to the vertical alignment of the (sharp) front sight with the (fuzzy) rear sight. I have to pay as much attention to the vertical alignment as to the horizontal alignment.

[quote="tleddy"]
The depth of field is a by-product of the iris, not the intent.

Tillman

As a 67yr. old diabetic, I must strongly dissagree. Prior to several eye surgery's, the use of an iris diaphragm, to adjust the depth of field, allowed me to continue shooting long after I would otherwise have had to stop. The device allowed me to sharpen the sights as my vision changed due to varying blood sugar levels during a match, and later on, deal with developing cataracts. For most of this time, I wasn't looking at the sights, but had to view them in silhuette against a bright target. I would even turn off the lights above the shooting position to help achieve this.
My eyesight eventually got so bad that I was unable to clear the sights, even with stopping the iris all the way down.

Thanks to the wonders of modern medicine, I've been able to return to shooting,. My eyesight is now 20/15 in my left eye, and 20/25 in my right. The loss of vision in the right eye is due to retinal scarring, and I now am cross aiming. I no longer use an iris, just a +.75 in my shooting glasses.

Paul

Don Nygord wrote quite a bit about vision, and, IIRC he always advocated using the iris to sharpen up the front sight (adjusting depth of field), with the accompanying changes in light level being an undesired by-product. For example, here is a quote from Nygord's Notes:

"Now what about low light? Well, when your natural pupil opens up everything gets "fuzzy" - most importantly, the front sight! And that is where the adjustable iris comes in: you close it until you get the sights sharp and leave the target "fuzzy"."

I remember another piece in which he described an AP match where he used the iris to sharpen the front sight, and the light admitted to his eye got uncomfortably low.

Perhaps rifle shooters use the iris (on the rear sight) to adjust light levels, but this is not what Don advocated for pistol shooting. Just to set the record straight.

FredB