Edge Distortion?

[texasgrunt]

I have a Leupold ERT 4.5-14x50 FFP. I noticed something awhile back, but forgot about it until seeing it again today. The extreme edges of the sight picture show a "ring" of distortion. And I mean extreme edge. This occurs at all magnifications until about 13X and then it moves completely out of the sight picture. It is even all the way around the scope and has a definite margin. Being new to scoped shooting I am going to ask the newbie question, "what is that and is it cause for concern?" I don't notice it until I use shorter than normal eye relief above about 6X. It is visible at normal eye relief below that.

Thanks in advace for the answers that are coming.

Grunt

[LR1955]

I have a Leupold ERT 4.5-14x50 FFP. I noticed something awhile back, but forgot about it until seeing it again today. The extreme edges of the sight picture show a "ring" of distortion. And I mean extreme edge. This occurs at all magnifications until about 13X and then it moves completely out of the sight picture. It is even all the way around the scope and has a definite margin. Being new to scoped shooting I am going to ask the newbie question, "what is that and is it cause for concern?" I don't notice it until I use shorter than normal eye relief above about 6X. It is visible at normal eye relief below that.

Thanks in advace for the answers that are coming.

Grunt

TG:

Is your ocular lens adjusted for your eye and did you remove the parallax at those magnifications? Probably won't solve the problem as that type of thing may be a quality issue in terms of the glass but it is worth a try.

LR55

[texasgrunt]

LR55,

Should the parallax be adjusted at low or high magnification? I adjusted it at 14X.

By quality issue, do you mean Leupold ERT's in general or an individual quality issue?

Thanks

[texasgrunt]

Yeah, never mind on the last post. I was confusing parallax and reticule focus. I will check the parallax adjustments ("focus" knob on the left side) tomorrow when it is light out. I may not have been adjusting it properly, as I just dropped the magnification and didn't change the parallax. Likely this is the issue. Told you I was a NEWB/FNG.

... and later that evening... I lied. I couldn't wait until tomorrow. I pulled the scope out, turned down the magnification and adjusted the parallax to the close range and it made no difference to the "ring". Hmmmmm.

The only thing I can think of is that I had to dial out the objective lens to get the reticule in focus for my eye. Could I possibly have it so backed out I am getting some sort of reflection of the tube wall? It is equal all the way around, so I don't think it would be that I somehow managed to warp the tube due to over tightening the ring.

Any other ideas out there?

[LR1955]

LR55,

Should the parallax be adjusted at low or high magnification? I adjusted it at 14X.

By quality issue, do you mean Leupold ERT's in general or an individual quality issue?

Thanks

TG:

Leupold doesn't have the greatest glass in the world. Most of the time when someone complains of that ring you describe, it is because of glass and or manufacture quality.

Might as well call Leupold but I wouldn't hold any hopes they will do much aside from telling you that the optic is functioning per their specifications.

LR1955

[texasgrunt]

Damn you're smart LR! I just had that conversation with Leupold and they said it is working within specification and the one the tech was looking through was doing the same thing. I don't think it is affecting the overall function of the scope, just maybe decreasing the field of view slightly. I don't know how to quantify what I'm seeing other than to say if the scope had a 100 unit radius, the refraction ring I am seeing would have an inside radius of about 95-97 units. However, for a $1400 scope I would expect to have no visual abberations like this. Maybe I ought to offload it and pick up a PST or something?

Grunt

[LR1955]

Damn you're smart LR! I just had that conversation with Leupold and they said it is working within specification and the one the tech was looking through was doing the same thing. I don't think it is affecting the overall function of the scope, just maybe decreasing the field of view slightly. I don't know how to quantify what I'm seeing other than to say if the scope had a 100 unit radius, the refraction ring I am seeing would have an inside radius of about 95-97 units. However, for a $1400 scope I would expect to have no visual abberations like this. Maybe I ought to offload it and pick up a PST or something?

Grunt

TG:

And can you believe that guys accuse me of being too cynical and or too critical of companies that charge top end prices for low end quality -- and or service? Never had a problem with the service from Leupold, though. Only their quality.

That said, if the optic serves your purpose, it serves your purpose. About the only thing is that if it really bothers you, it won't stop bothering you which means you will probably get rid of it. And then you are left in an ethical problem. Sell it without telling someone of its problem and let they return it if they actually are as astute about seeing that ring as you are. Or sell it at a huge discount while admitting that ring exists to a buyer.

Either way, next time get a Nightforce. You won't be bothered with that ring busines.

LR55

[urdaloser]

I have a Leupold ERT 4.5-14x50 FFP. I noticed something awhile back, but forgot about it until seeing it again today. The extreme edges of the sight picture show a "ring" of distortion. And I mean extreme edge. This occurs at all magnifications until about 13X and then it moves completely out of the sight picture. It is even all the way around the scope and has a definite margin. Being new to scoped shooting I am going to ask the newbie question, "what is that and is it cause for concern?" I don't notice it until I use shorter than normal eye relief above about 6X. It is visible at normal eye relief below that.

Thanks in advace for the answers that are coming.

Grunt

send it back, it's the glass...................

[urdaloser]

Damn you're smart LR! I just had that conversation with Leupold and they said it is working within specification and the one the tech was looking through was doing the same thing. I don't think it is affecting the overall function of the scope, just maybe decreasing the field of view slightly. I don't know how to quantify what I'm seeing other than to say if the scope had a 100 unit radius, the refraction ring I am seeing would have an inside radius of about 95-97 units. However, for a $1400 scope I would expect to have no visual abberations like this. Maybe I ought to offload it and pick up a PST or something?

Grunt

watch out for the pst, make sure to check the edges of the glass, I've seen distortion in those glass as well...