[shooter86314]

I have been struggling with fuzzy crosshairs for many years while shooting my M1A and other scoped rifles off the bench. I have found a pretty good combination of my progressive lens with a +.75 lens in my ClearSight device: a few days ago I saw my crosshairs clearly for the first time, an experience I wish to repeat frequently. But, the ClearSight flops around on my eyeglass frames and doesn't quite center on the point on my lens thru which I view the scope (near the upper left corner of my lens).

I decided that it's time to get a special lens for my Knoblochs which works for scoped rifles off the bench. Maybe I jumped the gun. I went to an optometrist today who fiddled with distance vision and clarity at 12 inches.

So, my question is: at what distance should the special lens focus to get best results? Do I need to get best focus at 100 yards or on the crosshairs in the scope, 6-9 inches away from my eye?

Thanks for any help.

 

[Bamban]

Can't you focus the eyepiece on you scope to get the crosshair in focus? I run +2.75 for my shooting lenses from ShootingSight LLC, but I don't use any lenses when shooting scope. I can focus the eyepiece to my eyesight. Anyone else who would use my rig will most likely not see the clear Xhairs.

My guess your scope should have enough adjustment for you to focus the reticle.

 

[nf1e]

What Bamban said.

 

[ShootingSight]

Your distance glasses are all you need, you do not need progressives.

Scopes have the built in ability to adjust the spherical value of the eyepiece, simply by twisting it, so it screws closer/further from the crosshairs. Scopes do not correct for astigmatism, so if you need astigmatism correction, that is why you need to wear distance glasses, or you could add a lens to the back of the scope, but that is a different issue.

What you want to do is find a white wall with good illumination, and aim the scope at it, so you don't have any image that is distracting you - just white with good contrast to the crosshairs. THen, you want to back the eyepiece out, unscrewing it all the way, or at least so far that the reticle is impossibly blurry. Finally, while looking through the scope, slowly screw the eyepiece back in, untill the reticle just comes into focus.

Now, when you look at an image, the target and the reticle should both be in perfect focus at the same time. You can obviously adjust it later to suit you, but generally, if you are looking at a target and the reticle at the same time, the target image will cause your eye to want to focus on the image, not the reticle, so it is more difficult.

Bamban, you have a -0.75 astigmatism. What you could do is get a -0.75 lens, have it cut to the diameter of your scope, and then (excuse the expression) duct tape it to the back of the eyepiece, after orienting it for your axis. That way, you will have both spherical and cylinder corrections on your scope.

 

[shooter86314]

ShootingSight said:

. . so if you need astigmatism correction, that is why you need to wear distance glasses . .

Yes, you got that right: I have astigmatism and prism in my progressive lenses. The sweet spot isn't very big. LOL. I understand what a pistol shooter means when he posts an ad: "Hardball gun for Sale. Front sight unused."

I rechecked the focus of my reticle today, without the ClearSight. It looks good on an overcast day with the scope pointed at brown rocks. The focus seems to deteriorate on a bright day shooting a bright white paper.

ShootingSight said:

Your distance glasses are all you need, you do not need progressives.

That is what I was looking for: use the distance prescription. I can center the Knoblochs behind the scope, and adjust as needed with the eyepiece. And even hang the eyepiece vertically, which might reduce distortion.

Thankyou, SS.

 

[ShootingSight]

We are misunderstanding here - you should not need knoblochs at all - just use your regular glasses.

You can do it with knoblochs if you insist, but they don't bring anything that your glasses do not.

Prism also does not matter. Prism is to help both your eyes align on an image together. Since you shoot with one eye, you don't care.
Progressive is also bad, that means the focus varies through the lens, so if you get it focused perfectly, as soon as you tip your head just slightly, your focus will change. I recommend single vision lenses with your distance values, so you can set the scope up, and it does not change as you tip your head.

 

[shooter86314]

the knoblochs let me center the lens on the scope. with glasses I am using the the top of the lens, about 1/4 inch from the edge.

update June 22. I received my "distance" lens for my Knoblochs last week. It improves my vision thru the scope immeasurably: both the cross hairs and target are now very clear.

 

[shooter86314]

range 7-9-2015

The prescription shooting lens has improved my sight picture considerably. When I adjust my scope properly and hold my head in the right position, everything looks sharp. Now I am finding fault with my scopes. I replaced the HBRII with the Weaver 24X target and shot a decent group, in the wind, even though I have to crawl onto the bench to get close enough to the eyepiece to to get a full field of view: the Arms-18 mount won't let me move the scope to the rear another inch.
Data is on the photo.

 

[ShootingSight]

Actually, get a lens the same OD as the scope, and then use tape to attach it to the back of the scope. Now you have a scope that is customized for you.

 

[shooter86314]

I bought a distance lens with astigmatism correction for my Knoblochs last summer, but I am now having difficulty focusing on the reticle of my new scope. (Leupod couldn't repair my '80s vintage 12X silhouette scope, so they sent me a new replacement.) My lens works well with my Weaver CT-24: the clarity is remarkable.

However, with the new Leupold, I get an intermittently sharp half-minute dot, which usually has a grey shadow, displaced about one dot diameter away at about 1:30. Today, I dry-fired at the range for over an hour, trying to get a sharp dot for more than a few second. With parallax adjusted, the target is clear and the dot doesn't move with my head. I adjusted the objective thru the entire range of adjustment.

Can anybody help? All I can think of is, the dot is so small that I can't focus on it.

 

[ShootingSight]

Start with the eyepiece screwed all the way out, and look at the sky, or at a white wall, while using your glasses, so all you see is the reticle. Start screwing the eyepiece in till the reticle is just clear, and stop. If you go further, it might still look clear, but your eye is starting to exert itself, which might make it clear for a short while, but it will begin to fatigue and blur eventually.

 

[JEFFJP_N_JJ]

I bought a distance lens with astigmatism correction for my Knoblochs last summer, but I am now having difficulty focusing on the reticle of my new scope. (Leupod couldn't repair my '80s vintage 12X silhouette scope, so they sent me a new replacement.) My lens works well with my Weaver CT-24: the clarity is remarkable.

However, with the new Leupold, I get an intermittently sharp half-minute dot, which usually has a grey shadow, displaced about one dot diameter away at about 1:30. Today, I dry-fired at the range for over an hour, trying to get a sharp dot for more than a few second. With parallax adjusted, the target is clear and the dot doesn't move with my head. I adjusted the objective thru the entire range of adjustment.

Can anybody help? All I can think of is, the dot is so small that I can't focus on it.

I tend to agree with you if you are speaking of the 'ten dot hot shot' contest here!? I cannot see the dots either...

 

[shooter86314]

SS: I will try that today. thankyou

I can see the circles OK, but I feel that focus problems are hurting performance: I can't call my shots. The 24x Weaver with half minute dot has great sight piture, but it isn't built for springer airgun; the M1A will beat it up.

lol. The dot I can't see well is the dot reticle in the scope.

thanks

 

[shooter86314]

silly me

I love it when a problem has an easy solution. When I went to the range today, I adjusted my eyepiece full range many times, never quite getting the dot focused. I shot a 5-shot group that measured about 7/8", struggling with focus.

I then asked another shooter to take a look thru my scope. He previously described his long range shooting, with some sort of Kelbly action, starting at 1000 yards, so I thought he might be able to offer some advice. He told me, "The dot is clear as a bell. It just pops!"

I thought it might be an astigmatism situation, cursing my special lens. Yesterday, I took the lens holder from the glasses frame and rotated it slightly while I looked thru it but didn't notice any improvement. Today, I made several small adjustments of my round lens and rechecked my focus. Voila! I can see again, better than ever.

I'm glad I didn't switch scopes today.

 

[Doc]

OK guys, I think most of you know this, but, from my personal experience --- when it come lens, glasses, and "seeing" -- listen to Art, he knows of what he speaks. Art has been a great help to me and I actually applied (transferred) what he helped me with for iron sights to my glasses for ATA Trap Shooting.....

 

[M1A's r BEST]

I have my scopes adjusted for use without my reading glasses.

1. I figure if I ever really need to use the rifle I probably won't have my reading glasses on me
2. If things get that bad I'll want to protect my glasses from loss/damage if at all possible, so I won't be wearing them if I still have them.

Just the way I look at it.

Adjustment is pretty easy, just loosen the lock ring and turn the back of the scope till things clear up, then tighten the lock ring again. But maybe my issue is different.

 

[ShootingSight]

I love it when a problem has an easy solution. When I went to the range today, I adjusted my eyepiece full range many times, never quite getting the dot focused. I shot a 5-shot group that measured about 7/8", struggling with focus.

I then asked another shooter to take a look thru my scope. He previously described his long range shooting, with some sort of Kelbly action, starting at 1000 yards, so I thought he might be able to offer some advice. He told me, "The dot is clear as a bell. It just pops!"

I thought it might be an astigmatism situation, cursing my special lens. Yesterday, I took the lens holder from the glasses frame and rotated it slightly while I looked thru it but didn't notice any improvement. Today, I made several small adjustments of my round lens and rechecked my focus. Voila! I can see again, better than ever.

I'm glad I didn't switch scopes today.

You probably want to set up an asitgmatism target to look at. When I make shooting lenses for people, they usually focus at around 48", so an 8-1/2 x 11 piece of paper will do. Take a sharpie and draw a + sign on top of an X, so you get horizontal, vertical and diagonal lines, hang it on the wall 48" from you, and now you can rotate the astigmatism lens until focus suddenly pops clear.

If it is a distance corrected lens, you need to get a slightly bigger target, so you can hang it at 30 feet and still see the lines.

You need lines in all directions because with astigmatism, you get different focus in different axes, so a left diagonal might be in focus, while a right diagonal is not.

Also, with an astigmatism, one position will give you perfect focus (actually, two, as you can rotate the lens 1/2 turn and get the same thing), while a 1/4 turn rotation will make your astigmatism twice as bad. So usually, between 2x as bad and perfect, most people can dial in the astigmatism axis with the proper target.

Here is a taget you can print:

https://dl.dropboxusercontent.com/u/18083950/Astig%20target.pdf

 

[shooter86314]

ShootingSight:

I did print a chart that I could use to evaluate the rotation of my lens. I adjusted until all lines looked uniformly black and clear.
But I couldn't buy a hit with my M1A and Leupold 12x scope.

I then shot the 10 shot dot challenge with my Rem700/6mm wildcat with Weaver 24x scope. The clarity was phenomenal, and I scored 10!!

I will shoot your Astig target at 100 yards. Thanks

 

[shooter86314]

In my recent post to the 10-dot challenge, I commented on a possible change to my M1A stock to facilitate vision. (Comment #139)

http://m14forum.com/rifle-competition/197069-ten-dot-hot-shot-contest-spring-2016-a-10.html

My Burris 6X HBR worked well on my Win52B but not on my M1A with oversized stock. My Weaver CT-24 worked well on my Rem700, which has a relatively thin butt stock. It occurred to me that my thick butt stock might be holding my head too far to the left to permit a clear sight picture. So, I filed a scallop into left side of the comb, about 3/16" deep X 3" long X 2" wide.

My resulting sight picture is remarkable: it stays sharp as I settle on the target and squeeze. Too much cheek piece was not the answer.

FWIW. I can see my brass as it is ejected.

 

[shooter86314]

On my recent visit to the range, I dry-fired on my astigmatism target. (Who drives 21 miles to dry-fire?) I finally was able to adjust both ends of the scope to see a clear dot and a clear target. I now need to adjust the angle of the round lens to remove the astig effects: the axis at 1 to 7 o'clock is clear, and the others are fuzzy. At home, I filed a line in the lens and several lines in the frame of the lens holder (with 30 lpi checker file) so that I can rotate the lens about 2-1/2 degrees per line and check my sight picture.