The Effect of Parallax Adjustment on Rangefinding?

[flmason]

Hi All,
   Was reading about parallax. Was thinking of AO or Side Focus move the reticle around to get rid of the parallax... it stands to reason that an incorrect setting would affect the accuracy of your reticle's hash marks, true or false?

[Lloyd Smale]

a ajustable objective or side focus does not move the crosshairs. It just allows the scope to be focused in at the range its being used at.

[flmason]

a ajustable objective or side focus does not move the crosshairs. It just allows the scope to be focused in at the range its being used at.

My understanding of this is that it moves the image plane of the reticle around? In doing so it must change size relative to the virtual image of the target? Which would lead to the scale being off?

At least that's what I was thinking.

[mcwoodduck]

It does two things.
1) it acts like a focus on binoculars giving you the clearest picture at the game.
 you take your rifle scope out to the range and set it to 100 yards.  and adjust the rear focus till it is clear.  that way you know that it is set at 100 yards.  So you can use the AO as a crude range finder.  Dial it till it is clear and flip the scope and look at the range based on the dial.    If you do nto focus the scope at a target when set at 100 you will then get a different reading. 
2) the AO seems to be best with small caliber and close ranges.  I have an AO on my elk rifle and really do not like it.
I have an AO on a target 22lr and love it as it allows me to shoot at targets really short range (under 100 feet) and get a nice clear picture) 
 

[flmason]

It does two things.
1) it acts like a focus on binoculars giving you the clearest picture at the game.
 you take your rifle scope out to the range and set it to 100 yards.  and adjust the rear focus till it is clear.  that way you know that it is set at 100 yards.  So you can use the AO as a crude range finder.  Dial it till it is clear and flip the scope and look at the range based on the dial.    If you do nto focus the scope at a target when set at 100 you will then get a different reading. 
2) the AO seems to be best with small caliber and close ranges.  I have an AO on my elk rifle and really do not like it.
I have an AO on a target 22lr and love it as it allows me to shoot at targets really short range (under 100 feet) and get a nice clear picture)

Hmm... scope hasn't arrived yet, so let me get this straight and in my case it's a side focus. So I was of the belief that the SF would sharpen up the image or the reticle, but the eyepiece focus was for the view....

With AO... it would seem to affect both. Do AO scopes also have the eyepiece focus.

Obviously I'm inexperienced here.

[mcwoodduck]

It does two things.
1) it acts like a focus on binoculars giving you the clearest picture at the game.
 you take your rifle scope out to the range and set it to 100 yards.  and adjust the rear focus till it is clear.  that way you know that it is set at 100 yards.  So you can use the AO as a crude range finder.  Dial it till it is clear and flip the scope and look at the range based on the dial.    If you do nto focus the scope at a target when set at 100 you will then get a different reading. 
2) the AO seems to be best with small caliber and close ranges.  I have an AO on my elk rifle and really do not like it.
I have an AO on a target 22lr and love it as it allows me to shoot at targets really short range (under 100 feet) and get a nice clear picture)

Hmm... scope hasn't arrived yet, so let me get this straight and in my case it's a side focus. So I was of the belief that the SF would sharpen up the image or the reticle, but the eyepiece focus was for the view....

With AO... it would seem to affect both. Do AO scopes also have the eyepiece focus.

Obviously I'm inexperienced here.

Maybe I can explain it easier.
With the Adjustable Objective on either the side or on the front it really does not matter.  It will focus either way.  Like binoculars.
Like binoculars it will focus no matter what you do with the focus on the eyecups.
What I was saying is this.  If you set the AO to 100 yards and use the eye peice to focus at 75 yards your ability to use the AO as a range finder is no longer accurate when focused at 200 yards. 
I just picked 100 yards you could focus at 25 yards.  The eye relief peice is going to focus for you at a point.  You need to make it comfortable for you and if it is comfortable and clear at a certain range that corosponds to your range finder then great.  You can rely on the range finder.  If not you just need to know how far off the range finder is and calculate before you use it for bullet drop.