Anybody using one of these? Im not to sure what 'side focus' means, anyone care to explain?

They are well made scopes...good glass...good turrets, but heavy and not much elevation.

Side focus is an alternate term for Parallax Adjustment.

TC

Thanks Topcat, im no optics guru, what's the significance of parrallax adjustment?

podunkkennels,


Since Topcat is not answering, I will chime in.

When you move your eye from side to side or up and down you will see the crosshair move when the paralax is set different from the distance you are looking. I saw severe paralax in a Pentax Game Seeker and returned it. Now I wont purchase anything without A.O. or S.F.

If you have side focus or adjustable objective you can set if for the distance you are sighting and the crosshair will not move. Everything I have except the Leupold 2 1/2-8X32 on my .454 has either S.D. or A.O. When I go hunting I set magnification on the lowest setting and the S.F. or A.O. on about 150 and forget it. That is unless I find something way out there. Then I have all the time in the world to play with my toys and set the paralax to the range the other toy (Leica 1200) told me it is. After all there is more to hunting than killing something or meat in the freezer.

Here's a little addendum.

On opening day of deer season I found some deer about a quater mile away in the binoculars. Nearby was a downed tree so I laid the rifle out on it and got into shooting a stable position. Very stable. I turned the magnification up to about 10X on the Bushnell 4200 4-16X40. I couldn'tmake out any bucks so I turned it up all the way. One had a big fork on one side and a small fork on the other side. There was no way for me to make out the antlers with an 8X binocular or even with the very nice scope set on 10X. I had time to adjust the A.O. to the distance to make sure the crosshair did not move just because I wasn't looking through the scope correctly. There is a real world value for a vriable scope.

Thanks Ringman, that makes sense.

All the scope's lenses are fixed inside a tube...the lens in your eye is not, so it can be in a different position every time you look through your scope.

Parallax is the term that describes how the crosshairs appear to move on the target because of head movements causing aiming errors.

The Side Focus knob allows you to "tune out" the aiming errors by setting the scope to the exact distance from the target...then your eye position relative to the scope doesn't affect your aim, so groups can be smaller.

When the Parallax is set correctly to the exact distance of the target, the image is also clearer, so "Side Focus" is more or less an accurate description.

All scopes have some Parallax, and the higher the magnification, the greater the error, so having the ability to fine tune the scope is a more important feature to have for scopes over 10x.

The basic marksmanship training concept of developing a solid cheek weld will help to minimize Parallax effects when your scope itself isn't adjustable.

TC

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/5755613/Weaver_Super_Slam#Post5755613

Thanks OT, I think the 2-10 fits my ticket a little better, 3-15 is way too heavy.