Focus dial or Parallax dial? (Ted ?!)

Forums Optics, Scopes, Rings, & Mounts Focus dial or Parallax dial? (Ted ?!)

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    james.dean
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    As suggested, I’m opening this topic to have à better understanding of the mistakes that are made about these two things, their importance when shooting, tips to erase these mistakes while shooting etc…
    That’s why I’m asking for your hep Ted, I’m sure your experience and pedagogy will deal with our problem ;)

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    Cookie
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    “Focus dial or Parallax dial”

    The second description you’ve used is passable/ok, though in my view will confuse the beginner. The issue on the other thread was a person’s incorrect use, and therefore apparent misunderstanding, on the fact that parallax is an error AS A RESULT OF incorrect focus between reticle and object. You dial focus to remove parallax error. That is an important point for people to start/simply understand that subject.

     

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    travels4fun
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    “Cookie”“Focus dial or Parallax dial”

    The second description you’ve used is passable/ok, though in my view will confuse the beginner. The issue on the other thread was a person’s incorrect use, and therefore apparent misunderstanding, on the fact that parallax is an error AS A RESULT OF incorrect focus between reticle and object. You dial focus to remove parallax error. That is an important point for people to start/simply understand that subject.

     

    
Cookie,

    Why don’t you take the initiative of creating a Guide to Parallax Adjustment so both new and seasoned air-gunners can benefit by understanding the subject better?

    Scott

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    Cookie
    Participant
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    There are so many existing guides to focus adjustment of scopes, mine wouldn’t have the credibility of say Leupold….

    http://www.leupold.com/life/help-desk/how-can-i-focus-so-the-reticle-is-clear/

     

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    travels4fun
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    How can I focus so the reticle is clear?
    One of the most misunderstood mechanical aspects of a riflescope is how to correctly use the eyepiece to focus the reticle. Here at Leupold, there are several kinds of eyepieces, but they all function similarly. All of them rotate—and in the process move in and out, changing the position of the eyepiece lenses in relation to the riflescope’s reticle. The reticle is the crosshair, or aiming point and the eyepiece’s primary role is to keep the reticle focused for the individual shooter’s eye.So, to focus the reticle, point the scope toward the sky or another distant, light colored background. (If the scope is mounted on a firearm, ensure that the firearm is empty and rendered safe before performing this operation.) If the reticle is not crisp when you first glance through it, glance away, and turn the ocular lens about ¼ to ½ of a turn in either direction and glance through it again. The reticle will appear to be either more or less focused at this point. If it appears more crisp, turn a quarter turn the same direction and glance through it again. If it is less crisp, rotate a full turn the opposite direction and check again. Repeat this process until the reticle is crisp and sharp. If the eyepiece has a locking mechanism, lock it in place at this setting.It is important to note that the reticle should not be focused while looking through the scope constantly. Your eye will compensate for the focus changes and focus will be very difficult to achieve. It is also important to note that the eyepiece focuses the reticle ONLY—not the target. Use the adjustable objective or side focus to remove parallax on the target (on higher magnification scopes). On lower magnification scopes, the parallax is factory set at 150 yards for most riflescopes, and shorter distances for other specialized products. (Rimfire scopes are set at 60 yards, for example.)By properly focusing the reticle, your scope will provide a crisp, clear aiming point, and a sharp sight picture that is ideal for accurately placing your shots on target.The above advice came from the this article: http://www.leupold.com/life/help-desk/how-can-i-focus-so-the-reticle-is-clear/

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    james.dean
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    Big thumbs up to for the last comments guys =)
    There just 1 thing I don’t understand… how can everything not be aligned ??
    I mean OK if you move your head, your eye will not match the center of the scope and reticule.. but that’s the only way to get a wrong alignment right? Or am I missing something?
    Also, to prevent this to happen, we can either use a soft plastic thing that we plug on the eyepiece or practise a lot… that’s it?

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    travels4fun
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    Understanding and Correcting Parallax by Cheaper Than Dirt:

    You see the term often used when describing scopes, but what exactly is parallax? More importantly, do you need to concern yourself with the parallax settings of a scope? Parallax describes a situation where the focal plane of the object in the scope is offset from the reticle. If you have parallax, you have an optical illusion that must be corrected. Parallax should not be confused with focus. Parallax compensation changes neither the focus of the reticle nor the focus of the image; it simply moves the planes at which these two objects are in focus so that they share the same plane (are coindicent). When looking through a high-power scope you identify parallax by adjusting your gaze slightly. If the reticle changes position on the target when you shift your gaze, your parallax is not properly compensated for at that range. The reticle appears to move in relation to the target image because the focal planes are not coincident, making it appear to be a 3D image. Properly adjusted, the reticle appears locked in place as if it were painted onto the target so that no matter how your gaze is shifted the reticle position never changes relative to the target. Consider the image below:

    In this illustration, the point where the focal lines cross and form an X is the focal plane for the target image. Note that it is in front of the reticle. When the angle at which you are viewing the image through the eyepiece changes, the reticle position relative to the target image changes.  

    In this illustration, the focal plane for the target image and the reticle are the same, so no parallax adjustment is necessary. It is possible to have an accurately placed reticle in the first image only if you are looking at through the scope with your line of sight exactly lined up with the reticle and target image. The problem occurs when your line of sight is not exactly lined up, as the point of aim indicated by the reticle is now incorrect. By eliminating parallax and having the target image and reticle on the same plane, you no longer have to have a precise line of sight: no matter what angle you are looking through the scope at the reticle will still accurately indicate the correct point of aim. Parallax is usually negligible or not present at all in most low-magnification tactical style scopes, as the scope is too short or the range is not long enough. 1x red-dot style scopes generally are parallax free at any range. Even mid-power hunting scopes have very little parallax, and many tactical models do not have parallax compensation, as it is impossible to quickly and accurately determine range in a dynamic tactical situation. In high-power scopes used over long distances you must compensate for parallax. High power scopes are usually equipped with a side-mount turret, or adjustment ring located on the objective bell, so you can move the focal plane of the target and reticle and eliminate parallax. Some of these rings or turrets are marked with various distances, generally ranging from 10 yards to infinity, indicating the proper setting to eliminate parallax. While helpful as a general starting place, these factory set markings are not always accurate. I find it helpful to manually determine the proper setting at 10 yard increments and mark those settings on the scope. Why is it so critical to get a precise parallax compensation setting? Because the amount of parallax increases with magnification, giving you a larger margin of error at higher powers if your parallax is not precisely corrected. For example, on a high-power variable 6-20x magnification scope parallax appears easy to compensate for at the lower 6x magnification setting. Once the zoom is increased to 20x it takes a very fine adjustment to completely eliminate parallax. To measure the actual parallax compensation needed for a given distance and zoom, head out to a range with known distances and calibrate your parallax adjustment mechanism. Some parallax adjustment systems, such as a side-mounted turret, have knobs you can use to “rezero” the mechanism. To get consistent parallax compensation, start with the adjustment knob or ring set on the stop past “infinity.”

    1. Make sure your scope has been zeroed for your rifle.
    2. Set up the airgun in a stable configuration aimed downrange at your target using sandbags or a machine rest.
    3. Make sure your target is the maximum distance possible at your shooting range. Preferably this is 100 yards, although shorter distances also work.
    4. Set magnification to maximum.
    5. Sight through your scope.
    6. Slowly shift your gaze while looking for movement of the reticle in relation to the target.
    7. Use the parallax compensation turret or objective ring to adjust the focal planes until there is no movement of the reticle when you shift your gaze.
    8. Usea fine paint marker mark the point on your ring or turret for this range.

    You can continue this process at various distances by moving the target closer and repeating the process. Permanently marking the positions on your ring or turret makes it easy to consistently return to that point time and again. Remember, when adjusting parallax using a side-mount turret, always start with the turret set against the stop past infinity and then turn it to the appropriate setting. This ensures that there is no slack or backlash to throw off your adjustment.

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    james.dean
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    So if everything is correctely set, you can move your eye all around the glass, the reticule will keep the exact same place on the target ?? As if it was printed on it ?!!!!

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    james.dean
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    Sorry for the question, I hadn’t finished reading it yet, I was just reacting as I started to finally understand something after reading approx a quarter of you whole answer ^^

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    james.dean
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    Holy freakin s*** … I’ve been doing it wrong since the beginning, moving my head on purpose when looking through the scope to try to identify why I couldn’t stop my reticule from moving to one point to another and trying to just deal with it…
    Thank you soooo much ^^
    I don’t think I’m a bad shot with 1.5 in or tighter groups at 110 yards with my pcp.. but, even if it’s not gonna be THAT impressive, I do look forward to my next groups as I think I’ll feel the gain of accuracy =)

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    Cookie
    Participant
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    I further point out that the distance markings on the objective or side focus are a GUIDE, not necessarily correct for your own set-up. Best to make your own marks against targets at set distances while the scope is clamped still. Finding those exact marks where reticle is still, is usually a revelation to shooters. As is usual for spectacle wearers, they need to be looking through exactly the same position.

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    james.dean
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    I can’t wait to try it now….
    Thanks again @travels4fun for this revelation, that’s the word =D

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    Ben10
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    Thanks for the advice on here Scott and cookie, I asked a while back about magnifications effect on parallax so I’m glad it has been cleared up. Thanks. 

    I have so many things to try out that I’ve learned from here, I’m hoping it will improve my shooting no end. 

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    AJ3
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    If the reticle is in proper focus using the eye piece and the target for any given magnification is brought into crisp focus using the parallax adjustment…is all good?  I am new to airguns and scopes in general but I am a bit confused at it sounds as if there may be a case where the target is not in crisp focus to remove parallax error?  I.e. Checking movement of the reticle on the target for different eye alignment vs target focus.

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    Cookie
    Participant
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    “…brought into crisp focus using the parallax adjustment…”

    You focus with either the objective or side focus; the parallax being simply an effect/error arising until focus of the reticle to the target is corrected.

    It is possible for the focussing to be out and have a shooter’s moving eye seeing a wandering reticle (with lots of parallax error available)……and yet, because their eye is subsequently positioned correctly they have removed all parallax error.

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    travels4fun
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    I’m glad you guys found this useful. Credit goes to Leupold and  Cheaper than Dirt for the articles.

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    17bullet
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    Sure I set my eyepiece focus for the cross hairs by quick looks at the sky. And if the scope has an adjustable objective lens it would be set on infinity. And then never adjust again unless my eyes change.

    Then for parallax adjustment I just turn the objective (or side knob) till the picture is in focus. If the cross hairs were set to be in proper focus in the first step then I believe when the picture also is in proper focus then both points are the same and with minimum parallax being present.

    But as a secondary help I also have my scope set for the long side of eye relief for 2 reasons. Recoil on powerful powder burners and also to help keep my eye straight and centered with the scope by seeing the narrow black ring around the picture view. When that black circle is perfect then my eye also is perfect which also eliminates parallax

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    ssunsera
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    Great thanks for travels4fun for that right up. As I had no clue. So point at blue sky and adjust for crisp crosshairs. In an air rifle your probaly done. But if you spent way to much money for a scope adjust the other focus to bring your other target into focus. Its all about 2 things not being the same distance and both being in focus.

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    travels4fun
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    “ssunsera”Great thanks for travels4fun for that right up. As I had no clue. So point at blue sky and adjust for crisp crosshairs. In an air rifle your probaly done. But if you spent way to much money for a scope adjust the other focus to bring your other target into focus. Its all about 2 things not being the same distance and both being in focus.
     

    I’m not sure I follow the last bit about spending way too much money for a scope.

     

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    Ben10
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    “17bullet”.

    
I like that idea but surely they absolute best place would be JUST so that you can’t see the black ring but if your eye was even just a fraction off alignment you would see the black ring?? 

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