The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: General

Reply
 
Thread Tools Search this Thread
Old May 22, 2018, 06:48 PM   #1
1stmar
Senior Member
 
Join Date: March 21, 2012
Location: Connecticut
Posts: 2,352
Parallax and ocular lens

Do adjustments to the ocular lens affect parallax? Ive not been able to find anything on this so assuming the answer is no.
1stmar is offline  
Old May 22, 2018, 08:08 PM   #2
std7mag
Senior Member
 
Join Date: June 23, 2013
Location: Central Taxylvania..
Posts: 2,527
Not that i'm aware of.
Usually you adjust the diopter in the ocular lens first. Then left alone.
Paralax is adjusted anytime distance changes.
__________________
This country was founded on two beliefs.
And I'm pretty sure pork rinds was one of them!
std7mag is offline  
Old May 22, 2018, 09:29 PM   #3
Aguila Blanca
Staff
 
Join Date: September 25, 2008
Location: CONUS
Posts: 11,871
Parallax is adjusted with the objective lens, not the ocular.
Aguila Blanca is offline  
Old May 23, 2018, 01:15 AM   #4
1stmar
Senior Member
 
Join Date: March 21, 2012
Location: Connecticut
Posts: 2,352
I understand the use of the AO and the proper way to adjust parallax. My question is if parallax is affected if i make an adjustment to the ocular. I dont believe it does or is supposed to but you are changing the position of a lens and therefore is seems logical it may affect parallax. Not sure every scope has an AO and most that dont are supposed to be parallax free at 100. If i change the ocular, is that affected.

Last edited by 1stmar; May 23, 2018 at 07:05 PM.
1stmar is offline  
Old May 23, 2018, 05:17 AM   #5
Mobuck
Senior Member
 
Join Date: February 2, 2010
Posts: 6,777
"Not sure every scope has an AO and most that dont are supposed to be parallax free at 100. If i change the ocular, is that affected."
Basically, no. Adjusting the focus of the ocular changes nothing beyond that.
Parallax free at 100? Often the verbage is parallax free to infinity.
Mobuck is offline  
Old May 23, 2018, 07:19 AM   #6
fourbore
Senior Member
 
Join Date: August 22, 2015
Location: new england
Posts: 1,045
Quote:
Originally Posted by 1stmar View Post
Do adjustments to the ocular lens affect parallax? Ive not been able to find anything on this so assuming the answer is no.
I read that is does. That was when a factory insider posted on another forum. That ocular bit can be hard to get right. If I remember right, not only does it effect parallax (and focus) but that needs to be right to get the optimum focus. That is beyond just getting a sharp cross hair.

I dont really know, this is just what I picked up from another source on the web. The sensitivity seems greatly magnified if you move up to these massive size variables like 6-24x or 8-32x and then maybe cheap out on the brand name.

In practical terms with any reasonable magnification, the conventional wisdom is that is will not matter.

OH, BTW, I believe most centerfire non AO scopes are set for 150 yards. If you miss a deer at 25 to 50 yards it wont be for that 1 inch parallax error. right? For varmint, you want the AO.
fourbore is offline  
Old May 23, 2018, 03:36 PM   #7
std7mag
Senior Member
 
Join Date: June 23, 2013
Location: Central Taxylvania..
Posts: 2,527
Mobuck,
Most( i didn't say all) scopes with no paralax adjustment( this includes the adjustable objective) are listed as paralax free at 100 yards.
__________________
This country was founded on two beliefs.
And I'm pretty sure pork rinds was one of them!
std7mag is offline  
Old June 3, 2018, 11:12 AM   #8
Flying636
Junior Member
 
Join Date: June 3, 2018
Location: Va mountains
Posts: 2
What's the best/appropriate way to adjust paralax?Pick a target and keep dialing the objective 'till it's clear?I know the numbers on dial are just a guideline.
Flying636 is offline  
Old June 4, 2018, 04:52 PM   #9
fourbore
Senior Member
 
Join Date: August 22, 2015
Location: new england
Posts: 1,045
Quote:
Originally Posted by Flying636 View Post
What's the best/appropriate way to adjust paralax?Pick a target and keep dialing the objective 'till it's clear?I know the numbers on dial are just a guideline.
"Just a guide" , it depends. The range numbers on a Leupold objective are very close, right out of the box.

The adjustment ring distance numbers can be "adjusted" on most quality scope. For example get your parallax to zero (no parallax) at 100 yards and then loosen the lock screws and rotate the numbered ring to read 100. This will allow use of a range finder and quick turn of the scope.

If hunting larger size game. Like deer, set the parallax to 150 yards and forget about.

Parallax is a big problem at close range. Close range and higher magnification. A good example where parallax can bite you is shooting squirrel at 10 yards to 100 yards with 12x scope.

Looking for a sharp focus IS NOT ADEQUATE. The only test that works for me is to secure the rifle very steady and move my head side to side and see if the point of aim moves.

A good rifleman will hold his head in the same position with every shot. If you can do that parallax becomes a very minor consideration for a very minuscule percentage of shooting activity.
fourbore is offline  
Old June 4, 2018, 05:07 PM   #10
1stmar
Senior Member
 
Join Date: March 21, 2012
Location: Connecticut
Posts: 2,352
Adjust the parallax while looking theough the scope, adjust till target is clear and sharp. Then check by moving ylur head behind the scope, the crosshairs should should remain on the same spot on the target deapite where your head is. Then adjust the ocular lens.
1stmar is offline  
Old June 4, 2018, 05:24 PM   #11
fourbore
Senior Member
 
Join Date: August 22, 2015
Location: new england
Posts: 1,045
I disagree, I adjust the ocular first.
fourbore is offline  
Old December 27, 2018, 11:41 AM   #12
kilotanker22
Senior Member
 
Join Date: October 14, 2012
Location: North Central, PA
Posts: 1,011
I know this is an old post, but figured I would offer my experience.

I agree with Fourbore. You really must adjust the Ocular first. There are a couple reasons for this.

1: The ocular adjustment serves no other purpose than to adjust the reticle to your eye. This being different for every person's vision. Has nothing to do with the construction of the optic.

2: After focusing the reticle to your personal setting then the parallax can be adjusted. Here is why. If the reticle is not focused for your eye in the first place, then the parallax adjustment may be in vain. If you don't have a focused reticle then the parallax problem isn't your biggest problem.

3: The need for Ocular focus is caused by the individual not the optic. The need for parallax adjustment is internal to the optic.

Also, I feel like Parallax isn't that big of a problem at longer ranges. It is a far more realized problem at closer range. Like 25 yards or less.

All that being said. No, Adjustment to the ocular lense will not impact the optics parallax setting. This is because Ocular focus is an external factor. Parallax is an internal factor to the optic. However, if the reticle is not focused to you personally. Then your parallax adjustment will likely be for naught.
kilotanker22 is offline  
Old December 28, 2018, 03:01 PM   #13
RC20
Senior Member
 
Join Date: April 10, 2008
Location: Alaska
Posts: 6,003
There may be no right or wrong on that. My take is:

My scope have the Parallax adjustment on front.

I just set them to the range and then the ocular is adjusted per my eye and the day (that changes some) - one scope is very prone to those light -CENSORED--CENSORED--CENSORED--CENSORED-s from cloudy to clear and how much daylight we have.

So if I change the ocular its after the Parallax has been set anyway.

I have yet to see any shift in POI from adjust the ocular.
__________________
Science and Facts are True whether you believe it or not
RC20 is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:10 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2018 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.05851 seconds with 8 queries