Side focus (parallax) help needed - Leupold 4.5-14

[Mike027]

Hi gang I am having a difficult time understandig how to properly use the side focus adjustment for parallax on my Leupold VX3 4.5-14LR with the BC reticle.

I guess my main point of confusion on this is that the scope instructions read "The side parallax adjustment knob is not to be used to focus the target image. If the reticle is first focused and the reticle then properly set, the image should be clear".

I must be doing something quite wrong because to get a really clear/sharp image of the target I need to adjust that side knob either forward or back depending on what power setting the scope is on and how far away the target is. This also gave me worries that the POI would be changing as I adjust the side knob.

Does anyone have an easy procedure for me to use to properly set the side focus knob on the leupold?

Thanks for any help you can provide. Mike

 

[Broz]

You use the focus ring on the eye piece to focus so the reticle / cosshairs are sharp. This is best done while looking at a clear sky with no objects in view.

Then once on target , use the side paralax knob to adjust out paralax. This is done by setting the rifle solid on bags or another rest, then move your head up and down or side to side while watching the target picture, but do not move the rifle. Turn the side paralax knob until their is no movement of the cross haires while your head moves. At this point you have ajusted out, or removed all paralax at that distance. Also, if there are numbers on your paralax knob, ignore them. They are seldom right and only put there to confuse you, like when Leupold wrote "Focus" on the side knob, it is best used to remove paralax not a focus.

Jeff

 

[Greyfox]

I have the same scope. First, the adjustment on the eyepiece is for focusing the Reticle so that it is sharp in the sight picture, than forget about it. The side knob is for parallax adjustment. The best way to adjust it is to first turn the knob until your target is in focus. You are not done yet. With the crosshairs is on target, hold the rifle very steady so it doesn't move and slightly move yor head/eye and fine adjust the side knob until the crosshairs does not move off your target point when you change your eye position in the scope. This adjustment should also be very close, if not the same as your best focus. Two points. Good practice is to always have your gun mount and head position while looking through the scope, the same. Second, is that the longer the distance, the less sensitive the adjustment. You will really see the effects of this at 100 yards. Much less so at 500+. What you are doing with this adjustment is placing your crosshairs in the same focal plane as your image/target. It corrects for allignment should your head/eye be off center. For speed, I mark the knob for 200 yards, 300,400, etc. It's much faster and is reproducible. If I am sighting in or doing closer range precision work, I'll adjust it by using the above technique.

 

[J E Custom]

You use the focus ring on the eye piece to focus so the reticle / cosshairs are sharp. This is best done while looking at a clear sky with no objects in view.

Then once on target , use the side paralax knob to adjust out paralax. This is done by setting the rifle solid on bags or another rest, then move your head up and down or side to side while watching the target picture, but do not move the rifle. Turn the side paralax knob until their is no movement of the cross haires while your head moves. At this point you have ajusted out, or removed all paralax at that distance. Also, if there are numbers on your paralax knob, ignore them. They are seldom right and only put there to confuse you, like when Leupold wrote "Focus" on the side knob, it is best used to remove paralax not a focus.

Jeff

+1

After adjusting the reticule and locking it down adjust the "side focus" for the best/sharpest image
it should be parallax free. check it like Broz said.

J E CUSTOM

 

[Edd]

Hi gang I am having a difficult time understandig how to properly use the side focus adjustment for parallax on my Leupold VX3 4.5-14LR with the BC reticle.

Read post #4.
http://www.longrangehunting.com/forums/f18/parallax-vs-focus-1988/

 

[Mike027]

Thanks for all the pointers. I think Im starting to understand how this works.
I just set the focus on th eyepiece and locked the ring down tight. I turned the side focus knob and lined up the infinity mark with the hash mark on the scope body (next to the side focus knob). When I looked at a close target (50 yards) I can clearly see the reticle movment when I move my head. When I turn the side knob in the other direction the movement eventually stops.

Its seems like I need to adjust the side focus knob to bring the target into focus each time I change the power setting so this brings me to the next question.

In a hunting situation will I (or should I if time allows) adjust the side focus knob for each shot?

Thanks. Mike

 

[Broz]

In a hunting situation will I (or should I if time allows) adjust the side focus knob for each shot?

Thanks. Mike

Yes, especially for long range hunting. The farther out your target is the more paralax will affect point of impact. For a long poke you need to eliminate all the error you can, every .25 moa counts.

Jeff

 

[Mike027]

Ok thanks but I have one final question just so I understand this fully.

When I am aiming at a target I should use the side knob to bring the target into focus.

When I have the target clear and focused does that mean I have eliminated the parallax?

Mike

 

[Broz]

When I am aiming at a target I should use the side knob to bring the target into focus.

When I have the target clear and focused does that mean I have eliminated the parallax?

Mike

No, you need to eliminate the paralax (crosshair movment) for a precise point of impact. In my book focus is secondary. If the image is slightly out of focus so be it. I want all paralax adjudted out before I shoot.

Leupold should have never wrote "focus" on that side knob. In my world it is not a focus it is indeed a paralax adjustment. When they wrote focus on the knob they just confused people.

Jeff

 

[Broz]

Here is something I wrote a long time ago for another forum.

Hope this will help you to see the purpose of adjusting this correctly.


Parallax Adjustment Done Correctly

Long ago I became confused when Leupold put "Focus" on the parallax Knob on the side of their "Long Range" scopes. I started looking into this and was amazed with what they were doing. In my mind, they may be coaxing a shooter to miss his point of aim. Let me explain. That little knob we find on the left side of a scope in not a focus to me. It is indeed a parallax adjustment.

First we need to understand what Parallax is. Here is a link to an explanation, you may not have to read it all to understand what is going on. http://en.wikipedia.org/wiki/Parallax

Now I know for a fact that if I use the knob to focus to the sharpest image sometimes I stall have parallax. The way to check this is, put your rifle on sand bags and position the crosshairs on a small target. Set it up so the rifle will not move with out you holding it. Then carefully looking through the scope without touching the rifle move your head up and down and side to side. If your crosshairs are moving around on the target you are experiencing parallax. Now while doing this, slowly turn the parallax knob one way then the other until even though you are moving your head, the crosshairs are staying on point of aim. Notice that in some conditions or distances, this no parallax view might be slightly out of focus. Don't let the out of focus thing bother you as I am here to tell you this is where your rifle will shoot the tightest groups. Once you have played with this process a bit you will be able to do it from a prone or bench position with much less effort. It might only be 1 inch at 100 yards, but that is 5" at 500yards. Defiantly worth making this process a regular part of your set up for each target you engage.

Jeff​

 

[Mike027]

Ok thanks Jeff for clearing that up for me. I guess I need to spend some time practicing and getting used to adjusting the parallax on distant targets. Thats unfortunate that the parallax might be adjusted correctly but I could still have a target that is not clear and focused. No system is perfect I suppose.

Thanks all for the replies. Mike

 

[Broz]

Ok thanks Jeff for clearing that up for me. I guess I need to spend some time practicing and getting used to adjusting the parallax on distant targets. Thats unfortunate that the parallax might be adjusted correctly but I could still have a target that is not clear and focused. No system is perfect I suppose.

Thanks all for the replies. Mike

Mike, the two are very close together. It will not be like a blurry image or something. But I feel it is best to get into the habbit of eliminating the paralax, and not worry so much about the focus.

Jeff

 

[Mike027]

I will put in some practice time on this. Im sure that will help.

On a side note I will soon be looking for a new scope to put on a 7mmRM Sendero that I purchased for Idaho elk. Im figuring on about $1,200 or so for a scope budget. I will save that discussion for another day. I will first check some of the archives to see what others are buying and recommending.

Thanks again for sending me the parallax info. It was very helpful. Mike

 

[Broz]

Mike, I will put my 2 cents in on the scope now. I would start watching for a used Nightforce NXS. A 5.5 ~ 22 x 50 or 56 You can get one used for usually about $1400 and some go as cheap as 1250 to 1300 but those are rare and go fast. If you can't find a 5.5 ~ 22 in you budget, then look for a 3.5 ~ 15 NXS. They have plenty of power for a 1000 yard shot. The Nightforce warranty is awesome (although I have never needed it and I have bought a slug of used NF scopes) The 5.5 ~ 22 has 100 moa of elevation and the 3.5 ~ 15 has 110 moa. They track great and return to zero. I don't think you would be disappointed. Plus the great thing about a used NF NXS is, it wil probably sell for what you gave for it if you ever wanted to sell it.

Good luck

Jeff