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Optical weirdness?

LongRange98

Private
Minuteman
Feb 20, 2022
51
15
California
Good day all, I noticed after mounting my Zeiss lrp s3 that the windage part of the reticle appears to be curving on the ends? The scope is currently on the middle of its travel & I’ve never seen this in any other scope any thoughts? Thank you.
IMG_3037.png
 
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You're not having much luck with scopes huh? lol I mean yeah the edges look like they're angled up a bit but that's a pretty serious manufacturing defect given it's an etched reticle.

Is the ocular screwed all the way in? That can distort the edges and give the image a fishbowl effect. Also, looking at things inside can play tricks on the eyes, try taking it outside and looking at something at a distance with a flat edge.
 
I think it's an illusion.

Go out and put it on a tracking target. Then test the turrets while you're there.


I think the narrowing of the reticle coupled with the open top makes it seem like it's sagging.

It's about impossible to tell without getting a decently focused picture with it focused on a nice straight edge.
 
Make sure your diopter is adjusted properly. Is it possible this is your first scope with a wide angle eyepiece, they tend to have a little more edge distortion than others. Hard to say without more data.
 
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You're not having much luck with scopes huh? lol I mean yeah the edges look like they're angled up a bit but that's a pretty serious manufacturing defect given it's an etched reticle.

Is the ocular screwed all the way in? That can distort the edges and give the image a fishbowl effect. Also, looking at things inside can play tricks on the eyes, try taking it outside and looking at something at a distance with a flat edge.

I’m really not lmao. Ocular is fine, elevation is in the center of travel I took it outside it looks the same. Will be hitting the range tomorrow and will take some better pictures.
 
I think it's an illusion.

Go out and put it on a tracking target. Then test the turrets while you're there.


I think the narrowing of the reticle coupled with the open top makes it seem like it's sagging.

It's about impossible to tell without getting a decently focused picture with it focused on a nice straight edge.
Good point, I will do a tracking test tomorrow & mess with the diopter a bit more see if that helps.
 
Make sure your diopter is adjusted properly. Is it possible this is your first scope with a wide angle eyepiece, they tend to have a little more edge distortion than others. Hard to say without more data.
You are right I need to eliminate some more variables, Will mess with the diopter some more & do a tracking test to narrow it down more.
 
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Field curvature. There are trade offs to not having it and lots of scopes have it. My guess is if you move your head up and down the reticle will look like flapping wings. I wouldn't be concerned and highly doubt its defective
 
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Field curvature. There are trade offs to not having it and lots of scopes have it. My guess is if you move your head up and down the reticle will look like flapping wings. I wouldn't be concerned and highly doubt its defective

I've noticed this on my S3 636. If your eye is not positioned in the center of the ocular, the edges of the reticle will "appear" to curve upward or downward.
 
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Here's a graphic showing how the back end of a scope looks when you take a pic of the back end and the axis of the cell phone and the scope are at an angle to each other/"cockeyed".

The rim/bezel of the rear of the scope forms a "ring", so if the optical axis of the cell phone and the scope are perfectly aligned then the ring would be equal in thickness and in this image it isn't because of foreshortening which is when one end or one side of something is extremely close to the front of an optic, it distorts in size.

In my graphic the top of the ring is closer to the optic taking the image, in the uploaded pic the bottom of the scope is closer to whatever took this image so the axis of one isn't lined up w/the other meaning one optic is at an angle to the other and cockeyed.

Whether it's another optic or your eyeball not lined up behind an optic where the optical axis of one ISN'T lined up w/the other, things will appear cockeyed.





Ring.jpg
 
I've noticed this on my S3 636. If your eye is not positioned in the center of the ocular, the edges of the reticle will "appear" to curve upward or downward.
I've seen it on a bunch of high end scopes. A couple that come to mind - TT 5-25x has some, the ZCO 4-20 it is very noticeable. Especially noticeable on low mag. And like you said, if centered no issue, only when I am not centered behind the scope.
 
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Unless it’s an anomaly from one of the adjustments he made, or a true defect, or picture angle, it certainly appears to smile a little bit…

I put one of my engineering straight edges up to the screen, and sure enough…. Look at the corners showing through.

IMG_1258.jpeg
 
The crosshairs on the actual reticle itself are probably straight as they can be, it's the projected image of the crosshairs coming through the back end of the scope that would have curvature of field, and my guess is that if the pic were taken w/one side of optic closer to the top of the scope (like in the graphic) then the crosshairs would be curving downward (frowning).

Could be wrong, but that's my inclination.

If you drew crosshairs on a sheet of paper then laid it on a basketball the paper now has a bulge (curvature of field instead of flat).
In spite of that, if you look @ the crosshairs "straight on", they'll still look straight.

Look at the curved sheet of paper from an angle (off axis one way or another), and the lines of the crosshairs will curve one way or the other, it would be impossible for them not to.

Most folks including me until I learned better, think of the image being projected out of an old movie projector as flat because the image is hitting a flat screen on the wall. That's an illusion, the image is bulged and only the central portion of the image/the central portion of the bulge is hitting the screen, everything else including resolution and illumination is trailing off at the edges if ever so slightly because it's curved.
 
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This is a parallax issue. If you know how the parallax is adjusted and point the scope at the proper range, this will go away.
 
The scope isn't pointing at anything, there's nothing in view except the crosshairs, in the pic at the top, and what he brings up about the crosshairs, so all this is before you start thinking about correcting for parallax.


At some other point in time, you point the scope at a target and set up the scope up for parallax, and it's perfect.


The next time you pick up the scope and rifle and place another optic or your eyeball behind the optic and if the axis of either one isn't lined up w/the centerline optical axis of the scope, you'll again have a mess regardless/wherever U point the scope.



The crosshairs are "cockeyed" because the optic taking the pic isn't lined up right behind the scope.


It's not going to go away because U corrected for parallax.
 
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If U "got it", then ignore this.


The object/the actual reticle itself has crosshairs on it that are straight as hell.



What you're seeing at the back end of an optic is something different/a different thing, which is a projected image of the reticle that suffers from "curvature of field" where the image is curved along w/any lines in the image like a set of crosshairs.

If you look at a circular object like a quarter from a particular angle U can see its curvature.

If you stand a quarter on its side, look directly above it, from that angle you don't see any curves, but something that appears "straight" across its width.


Both images are showing the same circular coin, only one is showing its curvature.



Think of the outer edge of the quarter as a crosshair, like the crosshairs of a reticle and the same thing/same principle (that looking at something from a different angle can make it appear straight or curved) applies to eye placement and/or a cellphone you've placed behind the scope re what U see thru the scope.


The irony is that even though you're seeing a projected image at the back of the scope that has some degree of curvature of field, the crosshairs you see will appear "straight" if your eye is centered and it's optical axis has merged with the centerline optical axis of the scope.

Said another way, your eye isn't at angle where you can see the curvature of the crosshairs, and believe me, the crosshairs are still curved, you're just not seeing it, so it appears straight like the crosshairs in the actual reticle.

The image by the OP at the top of this discussion shows the curve of the crosshairs when either your eye or a cellphone is off axis and not centered thus exposing what curvature of field does to the crosshairs in the projected image.



Qrectangle4-W.jpg





Qcurved24-W.jpg
 
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