40mm or 50mm???

Discussion in 'Long Range Scopes and Other Optics' started by LEFTYM77, Jan 2, 2008.

  1. LEFTYM77

    LEFTYM77 Well-Known Member

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    just want to get everyones opinion here, I am looking for a scope for my target / varmint rifle (savage model 12 vlp 243) and I have a few scopes in mind: the leupold vxIII LRT 6-20x40 or 50 and the bushnell elite 4200 6.5-24x40 or 50 tactical...I have been told that it is pointless to have a scope with over 16 power without the 50mm objective because it can't gather enough light to work with the higher powers??:confused: is there any truth to this or is it a sales pitch to get me to spend the extra on the 50?? this rifle will be used 90% off the bench / prone shooting paper and gongs
     
  2. royinidaho

    royinidaho Writers Guild

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    Light transmission is directly proportional to the size of the objective lens thus the larger the lens the greater the light transmission.

    Quality of glass and coatings is important also. My 42mm Weaver Tactical will stick with any 50 or 56mm I've compared it with after sun set.

    HTH..
     

  3. Flybuster

    Flybuster Well-Known Member

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    The bigger 50 mm will let more light in. On a varmint rifle your mainly hunting in broad daylight so thats not much of a factor, unless your state allows night hunting for coyotes and stuff.
    I own the Leupold VX-III 8.5-25x50 LR with fine plex. I am really fond of this scope for what I use it for, varminting and long range target practice. I haven't had tracking problems that I hear so much about. Its plenty clear at 1000 yards enough to resolve my target. I find no hinderance having a minimum power of 8.5 and while deer hunting a couple of years back I remember how well I could see after the sun had set and was starting to get dark.
    The long range series also has more elevation than the Bushnell 6-24. But I see that Leupold just raised their prices in Cabela's so I can see why Bushnell is looking so tempting. I think your on the right track, good luck.
     
  4. Down Under Hunter

    Down Under Hunter Well-Known Member

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    Go 50 plus. Cant go wrong.

    Cheers

    DUH
     
  5. LEFTYM77

    LEFTYM77 Well-Known Member

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    the bushnell 6.5-24x50 tactical is looking pretty tempting...anyone on here have any experiance shipping from optic zone ( or similar company) up to canada??
     
  6. J E Custom

    J E Custom Well-Known Member

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    If you hunt in poor light the 50 or 56mm is the way to go.

    But if you hunt in good light then a 40 or 44mm has the advantage
    of costing less and being lower on the rifle .

    J E CUSTOM
     
  7. PEI Rob

    PEI Rob Well-Known Member

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    I ordered one through Fronteir Taxidermy. CGN dealer.

    Cheers,
    Rob
     
  8. LEFTYM77

    LEFTYM77 Well-Known Member

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    the price difference from the us based companies is too drastic for me look past.. if the paperwork for the import permit is not too much of a hassle I think I will order one from south of the boarder....Is there anyone who has done this paperwork?
     
  9. Varmint Hunter

    Varmint Hunter Well-Known Member

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    IMO, it's all about the size of the exit pupil. The human eye can typically dilate to a maximum of about 6mm in low light. Maybe not even that far for aging eyes.

    You can easily determine the exit pupil of your scope by dividing the magnification into the objective diameter. For example: a 3x9x42mm scope would have an exit pupil of 14 when set @ 3x (which is way more light than is usuable by the eye), but would still have an exit pupil of 4.67 if set @ 9x. If you set the scope @ 7x you would have the magic 6mm exit pupil which is normally the most that you can use even in low light.

    Now - if you had a 3x9x50 scope, you would have an exit pupil of 16.7 @ 3x and 5.55 @9x.

    So what does the larger objective lens really get you? It gives you the ability to use slightly more magnification while still getting a 6mm exit pupil for use in low light. With the 50mm scope you could have your scope set at 8.3x, instead of 7x (with the 42mm), and you would still get a 6mm exit pupil. In normal daylight it is of little value.

    So is a 50mm or 56mm worth the extra weight, scope height and cost - only you can decide that, but the more I understand about optics the less I am attracted to the big objective scopes. Normally when the light gets low my scope isn't set to its maximum magnification anyway.

    This may be an over-simplification of the whole principal but I hope you will understand my point. For what it's worth, I've got 40's, 42's, 50's and a 56mm scope.
     
  10. Flybuster

    Flybuster Well-Known Member

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    I think that was a pretty good explanation VHunter. I think I remember reading a while back there was an optimum exit pupil 6mm anything over this optimum number the extra light was not noticable with the human eye? I was wondering if that was true.
     
    Last edited: Jan 5, 2008
  11. eddief

    eddief Well-Known Member

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    Just saved me some typing! These are the real facts. Well put VH!

    For me, I'll take the 40 & 42mm bells for the low mounting and good cheek weld. IMHO 50 and above is not needed especially when legal times in the US are 1/2 before sunrise and 1/2 after sunset.

    To each their own...shoot straight!
     
  12. Varmint Hunter

    Varmint Hunter Well-Known Member

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    It's not that the "extra light" isn't noticeable, it's that a column of light that is bigger in diameter than the dilation of your pupil falls outside of the receiving portion of your eye. At least that is my understanding.

    A larger exit pupil (than is usable for light entering the eye) does have one small advantage, you should be able to center your eye quicker in a wider column of light, thereby attaining a quicker sight picture. It may not be much but it's something.
     
  13. LEFTYM77

    LEFTYM77 Well-Known Member

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    great responces everyone!. I think I am going with the bushnell this time around It has everything I am looking for, for the 243 now I just have to decide where I am going to get it
     
  14. PEI Rob

    PEI Rob Well-Known Member

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    $540 us or $665CDN on this side, for the $125 I figured I would grab it because of the hassle. I didn't try to find an optics importer but if you find one that is fast and fair please let me know, lots of toys out there that need a home :D