To side focus or not

Discussion in 'Long Range Scopes and Other Optics' started by alloutsmith3, Feb 5, 2011.

  1. alloutsmith3

    alloutsmith3 Well-Known Member

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    Is side focus worth it enough to dismiss any scope that doesn't have? What are the real advantages and disadvantages of both? Thanks
     
  2. flyin lizard

    flyin lizard Well-Known Member

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    I am new to using the SF feature myself and I do like it better than having to reach out front to twist the A/O. Also its a much faster adjustment..
     

  3. oldreliable45120

    oldreliable45120 Active Member

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    The side focus helps you make fast adjustments. It'a very helpful in military and tactical environments. If you never plan on doing any tactical rifle match shooting or shooting where you are going to constantly change you range, it might not be needed. If all you plan on doing is normal shooting at paper and hunting, I wouldnt bother. Here is somthing to think about. Since the scopes invention in the late 1800 to present day, scopes didnt have side focus. I have quite a collection of rifles and only my tactical and target rifles have a SF knobs or an adj obj.
     
  4. MTBULLET

    MTBULLET Well-Known Member

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    Need it, no. Like it, YOU BET ! Worth it, yes .
     
  5. davewilson

    davewilson Well-Known Member

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    side focus is quite simply mechanically superior to an AO,front of the scope, type of adjustment. this is what Mr. Thomas of Premier scopes told me. side focus SF has all the parts in the center of the scope where it's supported by the mounts. AO has everything out on the end, where it adds more weight to unsupported areas. this gives the scope more flex under recoil. AO is one of the weak links,that gave Leupolds a bad name and was certainly their achilles heel.they simply won't point straight all the time changing the point of impact. the fix for the older AO models was to glue the AO in one spot.
     
  6. Broz

    Broz Well-Known Member

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    I don't think of them as a focus. I use them to adjust out the paralax. In fact in some cases when all the paralax is adjusted out at distances like 1000 yards you may be slightly out of focus. But this is where the tightest groups are shot. If I am looking at a scope for long range the side paralax is a must for me. I have seen it work with my own eyes.

    Jeff gun)gun)
     
  7. SBruce

    SBruce Well-Known Member

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    +1

    I can't even imagine trying to shoot precision with a high powered scope at any distance beyond maybe 300 yds without a way to adjust out the parallax.

    Parallax is really noticeable under 100 yds and out past 300 with any high powered (over maybe 12X) scope I've ever looked through, not to mention the image focus.
     
  8. azsugarbear

    azsugarbear Well-Known Member

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    It seems to me that most any scope runs into problems with paralax at longer ranges when the magnification gets above 10x or so. For real precision shooting, I like the 4.5-14x to 5.5-22x powered scopes with side focus.

    We often use the terms "focus" and "paralax" interchangeably, but this technically is not the case. I believe Dave King has a good explanation of both at the top of this forum heading.
     
  9. Broz

    Broz Well-Known Member

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    Exactly! That is why I mentioned that one may be slightly out of focus when all the paralax is properly adjusted out. I don't know who started this " Side Focus" term. My first memory of it was Leupold as they inscript it right on the knob. This sends bad info to many shooters and the knob is sed incorrectly more often than not.

    Jeff gun)gun)
     
  10. FAL Shot

    FAL Shot Well-Known Member

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    My front focus AO scopes are on a CZ 527 .223 Rem, CZ 527 .204 Ruger, CZ 452 .22LR, and BSA Lonestar .25 PCP.

    They do not recoil enough to warrant moving the focus to the center of the scope. Therefore, I don't worry about center focus.

    You can install a big ty-wrap around your AO focusing ring and leave the "knob" where it is easily accessed by the thumb as your hand supports your forestock. This is better than center focus for offhand shooting in the field under actual fast use hunting conditions. Just move your thumb up and down to focus your scope.....no need to move your hand back to the forestock like center focus requires. I can do this while my left hand is sling supported also.

    Wonder why nobody else ever mentions this way of focusing an AO ring??? It works. Try it.
     
  11. alloutsmith3

    alloutsmith3 Well-Known Member

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    Thanks for the input guys. Sounds like it would be worth it on a longer range rifle but maybe not needed on rifles for closes shots with less magnification.
     
  12. Matno

    Matno Member

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    I've got one of each...

    My Burris Signature 4.5-14x50 has an adjustable objective for parallax adjustment. Everything is in focus no matter where you look at any power magnification. Parallax changes when you turn the end of the scope. Unfortunately, that means you can're really use a flip-up scope cover. Won't be making the AO scope mistake again!

    My cheap side focus Simmons 6-18x40 (that actually has "SF" in the model designation) changes focus with the side knob. In fact, if I focus it at 50 yards, I can't really even see the target at 100 yards. Can't tell if the parallax changes much - i haven't shot it beyond 100 yards. Basically, it's worthless for quick shots at varying distances (which is okay since it's on my bench .22). Luckily, you only have to turn the knob a few millimeters to range it through it's full focal range. However, that makes it hard to "fine tune" the focus. Honestly, if your focus is off by 10 feet, the target will be blurry. Also, even at 6x it's tricky to get your eye in the right position. The eye relief has a range of about 1/4" outside of which you can see nothing. Also, the reticle is rotated about 5 degrees. It was a very low price, but I won't make the "cheap scope" mistake again!

    Next scope will probably be a Conquest or a Vari-X III to replace the Simmons. I'm keeping the Burris on my .300 win mag model 70 for now. Once I get a "real" long range gun, it's probably getting a Nightforce. My dad has a NF 8-32x56 on a Les Baer .308. I'm seriously considering getting the same combo, but probably with a 5-22x50.
     
  13. Sully2

    Sully2 Well-Known Member

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    I have AO focus on a 6-18 Leupold I have (22-250 heavy barrel) but..
    on a 243 heavy I have a Zeiss with side focus; a 260 heavy barrel a Zeiss side focus and on my 6mmBR a Zeiss side focus. A Heavy 25-06 AI thats Im having built will carry a Nikon with side focus.

    SF is quicker; IMHO more accurate and all in all seems to me to be more appropriate being where it is.
     
  14. tulku

    tulku Well-Known Member

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    I have both and use both . It's probably depends on what you're used to . My main Varmint rig carries a Fixed 16X Leupold with AO that after well over 10,000 Rounds , works as slick as butter . I'm so used to cranking that AO almost constantly in the Prairie Dog Fields , that I don't even think about it , and it ain't broke yet .....but it rides on a low kicking 223 . Have not used the SFs much yet , but future purchases will be based on other factors . AOs are not a problem for me.