Diopter match aperture eyepieces

[GBertolet]

Does anyone have any experiences with these. I have an HW match sight and I have trouble focusing on the target, as it is blured and runs together with the front post. I see them advertised with adjustable apertures and diopter lenses to help focus, and some even have polarizing filters. They ain't cheap, so I want to be sure they will do what I want.

[pneumaniatic]

What size is the diopter on your HW match sight? Most of the fixed diopters discs I've seen that come with match sights are on the small side (1.1mm, 1.0mm...etc), so you need good lighting on the target to use them. If you're using the stock one and it is a small diameter diopter, that should already give you the sharpest sight picture if you have a well lit target. I have a HW diopter on a R8 with a Gehmann 510 adjustable aperture and I like it much better than the fixed ones because I can open it up a little bit to let more light through and fine tune it to get the sharpest, and brightest sight picture.
The Gehmann 510 (adjustable iris only) can be had for $60 or so and IMO very worth getting. I've never tried the ones with the 1.5x mag lenses (I hear they are real nice), or the colour and polarizer filters.

[garyn]

GB
You focus on the front sight.

You are NOT supposed to focus on the target, it SHOULD BE blurred/fuzzy.
It is physically impossible for your eye to focus on a spot 30 inches in front of it (the front sight), and at the same time focus on the target 10 meters away.

You center the top of the front sight post in the center of the very fuzzy circle of the rear aperture.
You focus on the front sight.
You put the top of the front sight either just on the bottom of the fuzzy bull (think of a lolipop), or you put the top of the front sight in the middle of the fuzzy bull.

Also diopters are meant to be used under a certain minimum amount of light. If you are in a DIM room, the rear diopter size is likely too small to allow enough light in.

BTW, I have an adjustable iris on my match rifle. And as it turns out, the best position is the same as the stock fixed aperture.

[GBertolet]

Thank you pneumaniatic for responding. I just have the standard target aperture that came with the gun. I don't know the exact metric size, but it is fairly small. I wanted to get an eyepiece with an adjustable iris and optical lense to improve my focus. The better ones I have seen advertised, are adjustable from .5 to 3.0mm which range should cover all needs. I just wonder how much the optic lense improves focus? I really need improvement with my eyes!

[garyn]

GB
The primary purpose of the adjustable aperture is to compensate for ambient light level. More light, smaller aperture. Less light, larger aperture.

The adjustable iris will also increase the depth of field of focus, as you go SMALLER. Like when you squint your eyes.
BUT at a cost of making everything dimmer. So you need enough light to compensate for the smaller aperture. If you shoot outdoors in the sun, you will be OK.

You also need to be aware about fit. The adjustable apertures are typically for standard match sights. I have no idea if the threads on the old HW match sight is the same size. So where ever you buy it from, make sure you can return it if it does not fit.

When you say optic lens, are you referring to a 1.5x magnification lens? If so, it won't improve the focus, it is to magnify the sight and target image, usually for people with bad eyesight.

What kind of glasses are you wearing (single prescription, bifocals, progressive, etc), as this can have a big effect on your ability to aim?
And where on the lens are you looking out of when you aim the rifle? Typically right handed sportster rifle shooters aim out of the top left quarter of the lens.

ps my eyes are worse than 20/400 (the worse most eye charts go to) and I normally wear tri-focal progressive lens. Are your eyes worse than mine?

[pneumaniatic]

I'd like to add that garyn is right about focusing on the front sight. I have a hard time getting anything in focus sometimes because I have a heavy prescription and shooting right handed, I have to use the top right quarter of the lens to aim. By not looking through the optical center, everything gets blurred a bit. Scope crosshairs, red dots, front sights in irons / peeps are never in real sharp focus. If you can, try using a clear aperture front sight insert... I find it easier and nicer to use than the front posts for target shooting and plinking.

Also, yes, the old Weihrauch diopters (the real, 1/2 pound steel ones) will take any of the apertures from Gehmann, Anschutz, Centra...etc.
One thing about the magnified diopters, I think you can also adjust for something like +/- 4.5 diopters... so you can compensate for your prescription using those (as long as its not too heavy), or use a slightly positive diopter setting to help focus on the front sight. Please correct me if I'm wrong about this.

[garyn]

GB
pneumatic reminded me about the glasses.
You "might" need a new pair of glasses.
When I shot AP, I had a very hard time focusing on my front sight. My tri-focal prescription would not let me focus at 37 inches, where my front sight was. I had to get a pair of pistol shooting glasses made, where the primary prescription was adjusted (+0.50 diopter from my distance prescription) so I can focus on the front sight, and still see the target. Note, seeing the target means seeing the target enough to aim at it, it does not mean having the target in focus.

You can also try canting the rifle.
When I shoot my match air rifles, I cant/tip the rifle over to the left at 20-30 degrees. This allows me to keep my head upright and I am looking out of the center area of my glasses rather than the top left corner, so I can see better.

[GBertolet]

Yes, my eyes are getting tired with age. I had been advised to wear bifocals, which I have on a spare pair of glasses, but don't wear. As I stated earlier the front post and bull run together with no definition, of where one ends and the other begins. You are correct in saying that the bull should be slightly out of focus. But the problem I have, induces elevation errors, as you cannot see exactly how far you are up into the bull or how far below, within reason that is. The farther the target is away, the worse it gets. I had been advised once that optics in the eyepiece will get the bull more in focus and the aperture set on a smaller opening will increase your depth of field, provided there is enough ambient light available. Just like a camera on a high F stop setting. I have also been told that spring airgun recoil will ruin the optics in the eyepiece, as these eyepieces are intended for firearms not airguns. I dont know what to believe. I have the same trouble shooting the M1 and the AR at the DCM bullseye targets, but that's another story.

[garyn]

GB
few ideas
#1 if you can replace the front post with a globe aperture sight. Then you center the bull in the middle of the front aperture. For target shooting, it is a LOT easier than trying to use a post front sight.
#2 Use a 6-oclock hold. That way you put the front sight "just" under the bull (the bull is sitting on the post), hopefully making the bull easier to separate from the front sight.
#3 Use a sub-6 hold. This hold puts a space between the bull and the top of the front sight. The tricky part here is to be consistent in keeping the space the same. You need to find a reference to compare against. You could use the width of the front sight, or other visual reference as a comparison to adjust the space.

The magnification eyepieces ARE use on air guns, I use it on mine. But the new match air rifles have essentially ZERO recoil. Except that the sledge and sight on a FWB-300 does recoil.
I don't know how the magnification eyepieces will stand up to the 2-way recoil of a spring rifle. I am inclined to say they will do OK, as it is very simple, there isn't a recticle to jar loose like inside a scope.

[GBertolet]

Thanks for the info, garyn. I have an older HW35 which was considered a sporter/target rifle. It has a globe front sight with several types of post inserts including an annular ring. I would like to keep the post insert as I use the gun for plinking as well as bullseye shooting. Sort of a multi-purpose gun. With a 6 o'clock hold at 10 meters on a regulation target, I am good on tin cans out past 50 yards. That is when I can get half decent focus. It seems that the 1.5X eyepiece might be the way to go short of special glasses. I was given an optical loupe with 3 glass inserts that clips on the side of the glasses. I think it is called "Clear Sight". I experienced the trouble you mentioned in getting the loupe over the upper left part of my right eyeglass lense. Canting the rifle was your solution to move the vision area more to center.

[garyn]

Not only towards the center of the glasses, but also allows me to keep my head upright, which helps stability in the standing position.
The other problem w canting is the rifle is tipped to one side.
This is not an issue for me as all I shoot is at 10 meters.
But when you shoot at different ranges, not only will you have drop due to range you will have an offset to the side that varies at different ranges because of the cant.