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Parallax question (updated with pictures)

Posted By: Matt Hejl

Parallax question (updated with pictures) - 09/15/16 03:49 AM

I have an older scope that's 4-16 and it has a parallax adjustment on the front lens.

It has the numbers 2,3,4,5,8,infinity, 100, 150, and 50. They aren't in that order though...you have to go different directions to reach some of these numbers.

I kinda understand parallax, but what are the 2-8? And why different directions on the lens?

Thanks

See from first picture to last is me twisting the lens counterclockwise. I cant make sense of the numbers and the order they are in







Posted By: booradley

Re: Parallax question - 09/15/16 06:07 AM

I have no idea if the numbers are not in numerical order.
Posted By: QuitShootinYoungBucks

Re: Parallax question - 09/15/16 02:25 PM

They seem to be in order to me????

50
100
150
2(00)
3(00)
4(00)
5(00)
6(00)
Infinity
Posted By: Matt Hejl

Re: Parallax question - 09/15/16 02:46 PM

Originally Posted By: QuitShootinYoungBucks
They seem to be in order to me????

50
100
150
2(00)
3(00)
4(00)
5(00)
6(00)
Infinity


The 100 is to the left of the 150 mark, and the 50 is to the right of infinity.
Posted By: Jgraider

Re: Parallax question - 09/15/16 03:31 PM

Originally Posted By: Matt Hejl
Originally Posted By: QuitShootinYoungBucks
They seem to be in order to me????

50
100
150
2(00)
3(00)
4(00)
5(00)
6(00)
Infinity


The 100 is to the left of the 150 mark, and the 50 is to the right of infinity.


If I were guessing I'd bet you cannot just spin this AO around without it stopping somewhere (infinity), correct? If so, set it on the 50 and look at something 50 yds to see if it's in focus, then repeat at each distance. Once you get to infinity, I bet you can't just spin it over to 50, you'd have to reverse the twist all the way back around to 50 and start over. Clear as mud now?
Posted By: RiverRider

Re: Parallax question - 09/15/16 05:15 PM

Maybe the pitch of the mechanism's threads are different on each side of infinity to aid finer adjustment. I've never seen one like that. What's the make?
Posted By: Matt Hejl

Re: Parallax question - 09/15/16 06:09 PM

Originally Posted By: RiverRider
Maybe the pitch of the mechanism's threads are different on each side of infinity to aid finer adjustment. I've never seen one like that. What's the make?


Redfield...its an older 6x-18x
Posted By: Matt Hejl

Re: Parallax question - 09/15/16 06:10 PM

I have never used the scope, but if I mount it and look down it at a range...will I be able to tell if its set correctly by simply just focusing on things at different distances and seeing if its sharp?
Posted By: Jgraider

Re: Parallax question - 09/15/16 06:17 PM

Originally Posted By: Matt Hejl
I have never used the scope, but if I mount it and look down it at a range...will I be able to tell if its set correctly by simply just focusing on things at different distances and seeing if its sharp?


Yes, but you must focus the reticle first. Point the scope at the sky, focus the reticle until it's sharp. Then focus down range using the AO.
Posted By: QuitShootinYoungBucks

Re: Parallax question - 09/15/16 06:22 PM

Originally Posted By: Jgraider
Originally Posted By: Matt Hejl
Originally Posted By: QuitShootinYoungBucks
They seem to be in order to me????

50
100
150
2(00)
3(00)
4(00)
5(00)
6(00)
Infinity


The 100 is to the left of the 150 mark, and the 50 is to the right of infinity.


If I were guessing I'd bet you cannot just spin this AO around without it stopping somewhere (infinity), correct? If so, set it on the 50 and look at something 50 yds to see if it's in focus, then repeat at each distance. Once you get to infinity, I bet you can't just spin it over to 50, you'd have to reverse the twist all the way back around to 50 and start over. Clear as mud now?


It's a circle, right? Is 50 to the left of 100? List JGR said, I bet you can't spin it past infinity, you have to go all the way back around. If you can spin it past infinity, I'd throw it in the trash.
Posted By: RiverRider

Re: Parallax question - 09/15/16 07:22 PM

I'd verify where the stops are when you turn it to the limits in each direction to see if the adjustment ring has slipped.
Posted By: booradley

Re: Parallax question - 09/15/16 08:25 PM

Originally Posted By: Matt Hejl
I have never used the scope, but if I mount it and look down it at a range...will I be able to tell if its set correctly by simply just focusing on things at different distances and seeing if its sharp?


You don't need to mount it, or take it to the range to do that.
Posted By: RiverRider

Re: Parallax question - 09/15/16 11:01 PM

Now I can see the photos on my PC.

In the top photo I see 150, 2(00), 3(00), 4(00) yard marks.

In the middle photo I see 3(00), 4(00), 5(00), 6(00), infinity.

In the bottom photo I see the 5(00), 6(00), and infinity and the 50 yard mark which you would get to by turning the adjustment all the way back the other way. There's nothing goofy about the layout of the markings. It could be that the external ring has slipped, but that does not make the AO unusable.

Turn the objective all the way to through 4(00), 5(00), 6(00), and to infinity. Does it stop when you get to infinity, or go a little ways past it?
Posted By: Creedmoor

Re: Parallax question - 09/15/16 11:10 PM

Originally Posted By: Matt Hejl
I have never used the scope, but if I mount it and look down it at a range...will I be able to tell if its set correctly by simply just focusing on things at different distances and seeing if its sharp?


NOPE. Parallax adjustment has nothing to do with focus. And it's hard to explain.

Let's say that you have a target at 100 yards. When the parallax is adjusted properly, the reticle will remain fixed on the target when you move your eye side to side or up and down. If you move your eye and the reticle moves on the target, the parallax is not set correctly. There is a great explanation in an article that was written long ago by a professional in the optical business. I'll see if I can find it .........

Here you go:

http://www.snipercountry.com/Articles/Parallax.asp

I'd suggest that you bookmark the article and save it for future reference.
Posted By: RiverRider

Re: Parallax question - 09/15/16 11:16 PM

The simpler explanation of what the article is saying is that what you see looking "through" the scope is actually a real image suspended within the scope tube, and somewhere within that floating real image is the reticle of the scope. The AO moves the image to and fro within the scope tube so that some planar cross section of the image is in exactly in the same plane as the reticle, and that is where the "parallax-free" relationship between the reticle and the image exists.
Posted By: Creedmoor

Re: Parallax question - 09/16/16 01:03 AM

Correct. Problem is that to most people it's still clear as mud. roflmao
Posted By: LFD2037

Re: Parallax question - 09/16/16 01:52 AM

Originally Posted By: RiverRider
Now I can see the photos on my PC.

In the top photo I see 150, 2(00), 3(00), 4(00) yard marks.

In the middle photo I see 3(00), 4(00), 5(00), 6(00), infinity.

In the bottom photo I see the 5(00), 6(00), and infinity and the 50 yard mark which you would get to by turning the adjustment all the way back the other way. There's nothing goofy about the layout of the markings. It could be that the external ring has slipped, but that does not make the AO unusable.

Turn the objective all the way to through 4(00), 5(00), 6(00), and to infinity. Does it stop when you get to infinity, or go a little ways past it?

The 100, 150, 2, 3, 4, 5, 6(00) is to the left of infinity & the 50 is to the right of infinity. To me, that makes no sense!
Posted By: RiverRider

Re: Parallax question - 09/16/16 02:11 AM

It should stop as you pass through 5(00) to 6(00) and get to infinity, right? Then you turn it back the other way almost 360 degrees to get all the way back to 50 and it should stop again. Make sense?

Posted By: RiverRider

Re: Parallax question - 09/16/16 02:19 AM

Just noticed this...look at the set screw:





I could be wrong, but I'll bet that if things aren't currently lined up right, you could fix that by loosening that screw and repositioning the adjustment ring. There could be more than one set screw.
Posted By: LFD2037

Re: Parallax question - 09/16/16 03:27 AM

Originally Posted By: RiverRider
It should stop as you pass through 5(00) to 6(00) and get to infinity, right? Then you turn it back the other way almost 360 degrees to get all the way back to 50 and it should stop again. Make sense?


Well I'll be a monkey's uncle. That makes too much sense!!! hammer I feel like a dumbass now!
Posted By: RiverRider

Re: Parallax question - 09/16/16 10:38 AM

I think we all know that feeling!
Posted By: cxjcherokec

Re: Parallax question - 09/18/16 01:13 AM

You're starting point is the 50 mark (ie 50yds), most scopes won't adjust for parallax below that, some do but they are upwards of $2k The gap is a higher adjustment between 50 and 150 bc it's extremely hard to adj parallax at high power that close in range. Based on the purplish color I'd say it's an old leupold
Posted By: RiverRider

Re: Parallax question - 09/18/16 01:51 AM

Originally Posted By: Matt Hejl
Originally Posted By: RiverRider
Maybe the pitch of the mechanism's threads are different on each side of infinity to aid finer adjustment. I've never seen one like that. What's the make?


Redfield...its an older 6x-18x
Posted By: RiverRider

Re: Parallax question - 09/18/16 01:52 AM

So anyway, Matt, were you able to reposition the AO adjustment ring?
Posted By: Matt Hejl

Re: Parallax question - 09/18/16 02:49 AM

Yes...it all seems lined up now. I just need to take out and shoot and see how the marks line uo wih actual distances.

Thanks for the responses!
Posted By: RiverRider

Re: Parallax question - 09/18/16 04:04 AM

Well, good. Glad you got it straightened out!

Was I right about that screw, or did you handle it in some other way?
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