Scope cover from England improved parallax

Clark

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Oct 19, 2006
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I watched this Brit pellet gun video
12 foot pound pellet gun ranging is a lot like long range hunting with a 7mmRM, but divide all the ranges by 10.

he shows a lens cover called an accucover.



I Googled that and found
Products - Accucover
Accucover-parallax.jpg


I ordered one from England and it arrived today, 8 days later.

It really works.
I hunt deer at 400 -500 yards with a Leupold 2x7x32 [no parallax adjustment] with a Stoney Point turret for elevation, a Leica CRF 1600, a kestrel, a chart I make from Quickload/Quicktarget, a rear bag, and a swivel bipod.

The way I have been overcoming parallax is to back my eye way back from the eyepiece until the image is smaller than the eyepiece. Then I center the image in the eyepiece by moving my head. This works for target shooting, but is not fast.

The accucover allows me to have my head way forward, in the middle, or way back, and the target is centered fast.

I have made two pics while looking at the floor. My first pic has the camera sort of in line, and the second is out of line with the scope tube. You can see the fast correction from the second pic to the first would be to get the cross hairs to line up with the marks on the scope cover.
 

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If you simply put a circular aperture centered over the objective lines of any rifle scope it will reduce the exit pupil diameter which has the effect of limiting the maximum parallax that having one's eye off axis can produce. It will also dim the apparent image brightness if the exit pupil is smaller than your eye's iris and with a very small aperture reduce the optical resolution.

It does actually work. Using a scope with a objective focus, properly focused, works much better.
 
If you've focused your scope properly for target range, you won't have parallax at all. But that parallax thing on the website was pretty good at showing what it really is.

The anti-cant thing's interesting, but not all that important at reasonable hunting ranges.

Bart
 
I could see a benefit while using an optic with no parallax control.

However, I see no benefit in actually using a scope without parallax control of some kind.
 
Parallax control for a scope, either range focusing or not, is moving ones head so their eye's on the optical axis of the scope.

For a given target range and the scope's focused 10% further or closer to it, higher powered scopes will show more parallax error for a given aiming eye offset from the scope's optical axis compared to lower powered scopes.
 
I'm quite familiar with parallax error.

Attaching a little ring with arrows on my ocular housing is not as desirable as selecting an optic that can be adjusted to be parallax free at the distances I intend to shoot.
 
Bart,
When you were shooting that 3.325" 20 shot group at 800 yards that was in the May 1997 Krieger barrel advertisement, were you nulling out the parallax with a knob on the 20X scope, or centering your eye?
 
I truly hope you understand that I'm not advocating improper cheek weld and having your eye centered behind the optic. That's not what I was saying at all. It is important to be centered up, no doubt.

However, from my experience, when you dial out the parallax using the provided method on a rifle scope, whether it be side focus or adjustable objective, where the crosshair lays, is where the bullet goes. You can shift your eye out of position, and yet it does not affect the shot.

I'm willing to concede that on some rifle scopes of lesser quality, it would make a difference however.

On some scopes I've had, for instance. The image would be in focus, but parallax error would be present. In order to be parallax free, I would have to deal with an out of focus target.
 
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