Parallax or Side Focus Importance

[joeinaz]

Was looking at the Swarovski Z3 with the ballistic turret as an option. This scope does not have a side focus or parallax adjustment. How important is this feature if shots are 500 yards or less?

[azgutpile]

I would not get a long range scope without it.

Issues could start showing up after 400 to 500 yard range.

[lancetkenyon]

I agree, in my opinion, very important for shots over 300 or so.

 

Do you know how to check to verify parallax is eliminated once you have a scope with parallax adjustment? Just wondering if you have never used a scope with parallax adjustment, how much it matters at longer shots.

[Coues 'n' Sheep]

I have ranged elk effectively with the parallax adjustment beyond 400 yds.... it is an important and necessary feature and at times just plain handy, Hahahaha...

[GreyGhost85]

I agree, in my opinion, very important for shots over 300 or so.Do you know how to check to verify parallax is eliminated once you have a scope with parallax adjustment? Just wondering if you have never used a scope with parallax adjustment, how much it matters at longer shots.

Please expand Sensei!

[Titanium700]

Can't live without it.

Always playing with it on my Mark 4's

[lancetkenyon]

I can give you the Webster's Dictionary version, then try to explain in my own words how it works and greatly effects accuracy.

 

Parallax: The apparent displacement of an object observed by a change in position of the observer.

 

A good way, (the best way in my opinion), is to look at a target, even at 100 yards, and with the reticle in focus and not touching the rifle or scope at all, move your head up and down or side to side. You must have a very stable rest to do this. This is best done on higher magnifications. If the crosshairs appear to move on the target, your parallax is not adjusted correctly. So what parallax adjustment does is ensure the cross hairs and target are in the same "plane". So when you move your position of observation, like with a slightly different cheek weld, or going from prone to sitting or offhand, the reticle remains stationary.

 

Now if your parallax is not adjusted, and you are shooting 500 yards, and you are not consistent with your eye placement behind the scope, your reticle is moving on target, and you cannot aim at the same spot, even though it appears you do have the same point of aim. Making inches or more of difference at actual point of aim and point of impact without you even knowing it.

 

But you must be careful. Just because a scope's parallax adjustment might have graduated numbers for yardage, everyone's eyes are different, and scope tolerances can vary. So 400 might be 350 or 450 yards easily. A lot of scopes have a range where the parallax will be set, say from 500 to 600, and some are very touchy, only giving you a small margin of error.

 

It is such a habit of mine to check parallax, that I think I do it almost every time I get behind the scope. Even if I have it set and I am shooting at the same target distance for multiple shots.

 

For hunting, I usually leave mine set on about 200, because of the possibility of quick closer shots. A target at 100 yards will have less shift and be acceptable shift in POA/POI on a game animal.

[rcdinaz]

very good explanation... I would have just given the head moving exercise, this has much more detail.

 

If is funny that this is one thing I did not spend much time on with my girls but on the rifle they have been shooting most they have said "it looks funny", caught me forgetting that last final step.

[duckhunter175]

Great explanation! Thoughts or preferences? I've seen the AO style scopes then side focus... Just shooter preference? I see now that Kahles is putting it on top under the elevation???

[trphyhntr]

no wonder i cant hit anything

[lancetkenyon]

Love the parallax on the side or top like my Kahles. Not a fan of the adjustable objective on the bell housing. Much easier to access than reaching to the front of the scope.

[Chef]

A great analogy for describing parallax is:

 

Imagine riding in the passengers seat and looking over at the speedometer cluster. The reading you see is different than that of the drivers. Even though you are going th same rate of speed. Parallax.

[n2horns]

Like all stated, use it if you have it on the scope. It is there for a reason. Good explanation all.

[Tdub]

I was worried about the parallax adjustment because at first I would forget to adjust it. I came across this video which helped me to better understand what it does. Seems to go along with what Lance is saying.

 

https://m.youtube.com/watch?v=6ziKTDIMCig