• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

Parallax shift

What causes a parallax shift? Is it temperature or barometric pressure? I’m shot 2 days ago it was 55F and 30.19”. I shot again yesterday at 68F and 29.93”. The parallax settings were different at each yardage marker (did the whole head nodding without touching the rifle until the reticle didn’t move at least vertically can never get the horizontal movement out of my NightForce 5-25 ATACR but I guess that’s be a different topic). Anyways the setting were different by a fair amount on the two days so I’m just wondering what is the cause of that?
 
What causes a parallax shift? Is it temperature or barometric pressure? I’m shot 2 days ago it was 55F and 30.19”. I shot again yesterday at 68F and 29.93”. The parallax settings were different at each yardage marker (did the whole head nodding without touching the rifle until the reticle didn’t move at least vertically can never get the horizontal movement out of my NightForce 5-25 ATACR but I guess that’s be a different topic). Anyways the setting were different by a fair amount on the two days so I’m just wondering what is the cause of that?

Different refractivity of the atmosphere
 
I do not pay any attention to the range indicator on the parallax turret.
Just me of course
I find I'm usually dialed a lil past specified yardage on parilax knob to get clearest picture.
 
I find I'm usually dialed a lil past specified yardage on parilax knob to get clearest picture.
I shouldn't, but light conditions dictate a lot of this, the next hour you may need to be focused 100 yards in front of said target.
I got into buying Kahles optics in the last 3 yrs, and most of my understanding concerning parallax kinda went out the door. I can set my parallax at 300 and run targets to 1350 without even a bump of the knob.
I also run a couple F1 NF atacr's, you can experience the same some days, but on other days you wonder just how many spins the knob is supposed to yield in it's lifetime, because you work it hard.
I honestly do not get horizontal parallax w/o vertical, and would love to see it.
 
I do not pay any attention to the range indicator on the parallax turret.
Just me of course

Yes same here. There really shouldn't be any numbers or anything on that knob. The picture is either parallax free or it is not. The other thing it is NOT is a range finder.
Somewhere I read about how that knob should be turned meaning, all the way in one direction and then stop when parallax is gone. Not to keep going back and forth with it. Unfortunately I do not recall where I read this nor do I recall the procedure however it has something to do with the mechanics inside the scope. I'm reaching here.
 
Last edited:
I don’t use the numbers on the parallax knob to line up with the yardage I’m shooting either. I will record it for a reference to see if a pattern develops. That might be a waste of time but it’s not hurting anything either.

Milo: I can try to record the horizontal shift while the vertical doesn’t move with my cell phone next time I’m at the range but I’m not sure how that will turn out... I’ll do my best though
 
I don’t use the numbers on the parallax knob to line up with the yardage I’m shooting either. I will record it for a reference to see if a pattern develops. That might be a waste of time but it’s not hurting anything either.

Milo: I can try to record the horizontal shift while the vertical doesn’t move with my cell phone next time I’m at the range but I’m not sure how that will turn out... I’ll do my best though
I did not say it was not going on, do try. I am not a scope connoisseur, parallax as I understand, focus to clear sight pic, no fuzz on the edges, lol
 
I have several NF NXS scopes and a couple NF ATACR SFP scopes. While I never have issue with setting parallax on the NXS I always (read never) have problems getting it correct for the ATACR.
To make things even more "fun" I have four NF Comp scopes and they don't deal me fits on parallax like the ATACR.
 
I have several NF NXS scopes and a couple NF ATACR SFP scopes. While I never have issue with setting parallax on the NXS I always (read never) have problems getting it correct for the ATACR.
To make things even more "fun" I have four NF Comp scopes and they don't deal me fits on parallax like the ATACR.
I do know that the ATACR and the F1 ATACR only share the name. The F1 has better glass, way bigger eyebox, a fraction of the tunneling from 5-7 power, and way less travel on the focus knob. I'm not saying it is any easier to focus though. It eats my lunch on occasion. The old NXS were sweet scopes.
 
So I contacted NF and got this back “When they check the optic in the final stage of assembly they only check up and down. He told me you can often times get them close but more often than not going side to side will cause varied results. The other thing in real world shooting rather in the factory environment is mirage. This comes form both the atmospheric conditions and the rifle barrel, both will influence what you are seeing. Try to just check for parallax using vertical movement and see if that helps.”
 

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
165,785
Messages
2,203,143
Members
79,110
Latest member
miles813
Back
Top