This is the best explanation of Rifle scope Parralax I've seen ! Short and easy to understand !!!
Even MY one eyed ass can understand this !!!
Parralax Explained
- Thread starter JoeWayneRhea
- Start date
The next video up from YouTube gives a bit more explanation about how much Parallax can impact your shot.
They start the discussion on the amount of deviation at the 5:00 minute mark. If the parallax is set to 150 yards, and the target is 300 yards, the error is about 44mm. At 600 yards, 88mm possible error.
Take that down to airgun ranges, under 100 yards. If the target is at 15 yards (1/10th of the above measurements for easy math), and the target is at 30 yards, the possible error is 4.4mm. Let's see, a .177 pellet is 4.5mm, so the possible error is around the size of a .177 pellet.
As most rimfire scopes are set to 50 yards, Parallax error down to 25 yards is around (without doing the math) the width of a .22 pellet at 5.5 mm.
So, if I'm shooting starlings at 100 yards, parallax is probably important. If I'm shooting extreme benchrest, it's important. If I'm shooting racoons at 30 yards, it doesn't mean much. Even grey squirrels are big enough to not worry about parallax all that much.
Yes, I want parallax knobs on the scope, but do I really need it for my style of shooting? Maybe not????
Anyone want to check the logic of the above is welcome to do so.
They start the discussion on the amount of deviation at the 5:00 minute mark. If the parallax is set to 150 yards, and the target is 300 yards, the error is about 44mm. At 600 yards, 88mm possible error.
Take that down to airgun ranges, under 100 yards. If the target is at 15 yards (1/10th of the above measurements for easy math), and the target is at 30 yards, the possible error is 4.4mm. Let's see, a .177 pellet is 4.5mm, so the possible error is around the size of a .177 pellet.
As most rimfire scopes are set to 50 yards, Parallax error down to 25 yards is around (without doing the math) the width of a .22 pellet at 5.5 mm.
So, if I'm shooting starlings at 100 yards, parallax is probably important. If I'm shooting extreme benchrest, it's important. If I'm shooting racoons at 30 yards, it doesn't mean much. Even grey squirrels are big enough to not worry about parallax all that much.
Yes, I want parallax knobs on the scope, but do I really need it for my style of shooting? Maybe not????
Anyone want to check the logic of the above is welcome to do so.
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Most of us use the parallax correction dial as a focusing tool and a range guide. The parallax issues faced by long range powder burner shooters is different but we tend to have similar requirements for airguns scopes.
If you never go above 6x on a deer rifle, you don't worry about it but if you zoom in to 12x or 16x on a squirrel gun, you need a scope with parallax correction and an extended focal range.
Now, people might be tempted to point out the difference between parallax correction and focus but while there is a difference, for our purposes, if we are able to focus the scope, we don't usually have to worry about it.
If you never go above 6x on a deer rifle, you don't worry about it but if you zoom in to 12x or 16x on a squirrel gun, you need a scope with parallax correction and an extended focal range.
Now, people might be tempted to point out the difference between parallax correction and focus but while there is a difference, for our purposes, if we are able to focus the scope, we don't usually have to worry about it.
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Zebra - "Now, people might be tempted to point out the difference between parallax correction and focus but while there is a difference, for our purposes, if we are able to focus the scope, we don’t usually have to worry about it".
Go on then, explain to me the difference between Focus and "parallax correction" / what the side wheel (on modern scopes) actually does ???
I'll give you a 'starter for ten' - you can no more 'correct' Parallax than you can 'correct' Gravity (& certainly not by twiddling a little knob on a scope
).
Go on then, explain to me the difference between Focus and "parallax correction" / what the side wheel (on modern scopes) actually does ???
I'll give you a 'starter for ten' - you can no more 'correct' Parallax than you can 'correct' Gravity (& certainly not by twiddling a little knob on a scope
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In theory you can correct for parallax without it being clearly focused and vice versa. When parallax is corrected for, the crosshairs don't move when you move your head. When focus is corrected, you can see clearly. If a scope is working properly though, they should coincide. While parallax correction might be a small issue for airgun distances, focus is always important."BRS"Zebra - "Now, people might be tempted to point out the difference between parallax correction and focus but while there is a difference, for our purposes, if we are able to focus the scope, we don’t usually have to worry about it".
Go on then, explain to me the difference between Focus and "parallax correction" / what the side wheel (on modern scopes) actually does ???
I'll give you a 'starter for ten' - you can no more 'correct' Parallax than you can 'correct' Gravity (& certainly not by twiddling a little knob on a scope
May I suggest that you try being a little less.... what's the word.... I know it's what the French call a "shower" .... it will come to me. Nobody likes a smart... um... what's the word.... I know it has something to do with donkeys in the Bible.
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OK, so (& ignoring your personal comments)
This statement (by you, Zebra) I can agree with - "When focus is corrected, you can see clearly".
This statement, however has absolutely no place in a grown-up discussion on the Natural Phemonenon called Parallax,
"In theory you can correct for parallax without it being clearly focused and vice versa"
Parallax does not exist entirely within a rifle scope tube, cannot be corrected (it's a constantly variable factor; there is no 'Correct' point) it is purely the alignment then MISALIGNMENT of three parts within an optical scenario (In our case & using the standard optical conventions Object (target) / Reticle / Ocular (eye).
Move any one of those 3 parts out of their Planar alignment and Parallax will come into play, (since the reticle is best thought of as 'Fixed' and the Object is at a far distance the usual culprit is Head Position. An incorrect Head Position (or not repeated head position) may be a result of the user trying to alter the focus of one element (subconsciously) but one element being out of focus (in the standard optical trio; Object, Element/Reticle & Eye) does not 'open the door to Parallax'.
To summarize
The Adjustable Objective lens ring or the small adjustable knob on the left of many modern scopes do(es) one thing only,
They adjust the Focus of the Objective Lens so that the optimum point of the image 'cone' falls onto the same plane as the Reticle lens (and that is where your Ocular lens should be set to .. the Reticle). That is to say they adjust the Objective lens(es) for the distance from the target. That is all they do - no magic.
This statement (by you, Zebra) I can agree with - "When focus is corrected, you can see clearly".
This statement, however has absolutely no place in a grown-up discussion on the Natural Phemonenon called Parallax,
"In theory you can correct for parallax without it being clearly focused and vice versa"
Parallax does not exist entirely within a rifle scope tube, cannot be corrected (it's a constantly variable factor; there is no 'Correct' point) it is purely the alignment then MISALIGNMENT of three parts within an optical scenario (In our case & using the standard optical conventions Object (target) / Reticle / Ocular (eye).
Move any one of those 3 parts out of their Planar alignment and Parallax will come into play, (since the reticle is best thought of as 'Fixed' and the Object is at a far distance the usual culprit is Head Position. An incorrect Head Position (or not repeated head position) may be a result of the user trying to alter the focus of one element (subconsciously) but one element being out of focus (in the standard optical trio; Object, Element/Reticle & Eye) does not 'open the door to Parallax'.
To summarize
The Adjustable Objective lens ring or the small adjustable knob on the left of many modern scopes do(es) one thing only,
They adjust the Focus of the Objective Lens so that the optimum point of the image 'cone' falls onto the same plane as the Reticle lens (and that is where your Ocular lens should be set to .. the Reticle). That is to say they adjust the Objective lens(es) for the distance from the target. That is all they do - no magic.
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That's what the world calls "adjustable parallax" with the alternative being scopes with "fixed parallax".
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I've been wondering about this for while as well. Which holds priority, the clearest focus possible or a reticle that's staying put. I've settle on keeping the reticle in one place and still adjusting for focus as much as I can get by with, not that there is a lot of difference. Was also wondering if my Hawke SW or SWFA 16X would be prone to more parallax error than a $2500 scope, probably so I'm guessing. How do you guys prioritize parallax error vs focus. Would be great if one solved the other but I still see the guys even with the really high end stuff doing the head bob so that's probably not going to happen.
jk
jk
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Just me personally, I set for Parralax and then tweek the sight picture if needed by using the eyepiece focus . The eyepiece gives you a little wiggle room where you can usually get a great sight picture and no parralax. With some scopes you have to choose . When I do I choose parralax free. But then VERY shortly thereafter, I choose to sell the scope asap
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I don't think any scope is more or less prone to parallax error than another. It's governed by the physics of light and lenses.
Any fixed parallax scope will have parallax issues, unless whatever you are looking at is at the same range that the scope is focused for.
Any adjustable scope will have the same type of issues as another when it comes to parallax.
Now, focusing at the eyepiece is a different matter completely, but focusing the image of objects downrange onto the same plane as the reticle is about the same for all scopes, with the same amount of reticle wander. It's just how light works.
Any fixed parallax scope will have parallax issues, unless whatever you are looking at is at the same range that the scope is focused for.
Any adjustable scope will have the same type of issues as another when it comes to parallax.
Now, focusing at the eyepiece is a different matter completely, but focusing the image of objects downrange onto the same plane as the reticle is about the same for all scopes, with the same amount of reticle wander. It's just how light works.
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Exactly! Why would anyone keep a scope if you couldn't achieve a clear focus and correct for parallax at the same time??"JoeWayneRhea"Just me personally, I set for Parralax and then tweek the sight picture if needed by using the eyepiece focus . The eyepiece gives you a little wiggle room where you can usually get a great sight picture and no parralax. With some scopes you have to choose . When I do I choose parralax free. But then VERY shortly thereafter, I choose to sell the scope asap
This isn't something you only find on high end / high dollar scopes like hyper precise turrets. This is something you would expect to be about right on any scope you would want to mount on your rifle.
We all have different needs but not in this respect. We all want our scopes to be clear. It's like toilet paper. You can negotiate with us on many things but some we just need to be there to avoid a nasty surprise at the wrong time.
I think it is most likely to be an issue if a scope is chosen with too much magnification for the price point. If you want a scope with 50x, make sure to pony up for a decent one that's properly made.
The highest power scope I have is 24x but, with a semi decent scope, I can see the pellet holes on the target clearly at 150 yards on 14x so I see no need to live with any parallax problems.
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I feel better now and maybe I'll sleep better tonight... curiosity got the best of me so I took each one of my AG's out with no plans to shoot just check out the focusing vs parallax error. The Vulcan, FX400 and FX500 all have the same scope, Hawke 6.5-20X42 on them. Focused on a news paper ad at my 100 (98yd) target and got it precisely focused and then checked the parallax with the head bob. Honestly and fortunately I don't think any other tweaking of the side focus knob would have done any good (in a good way). I also checked my Regal with its SWFA 16X and basically the same results. Guess its not really an issue after all. I may drink a beer on this one...
Jimmy
Jimmy
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Drink one for me too Jimmy ! All my scopes focus and parralax free at Same time. Another of the 50,000 reasons to avoid cheap scopes if at all possible !!
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