50mm scope vs 40mm/42mm etc...

Discussion in 'Long Range Scopes and Other Optics' started by emmagator, Nov 14, 2010.

  1. emmagator

    emmagator Well-Known Member

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    What is the main reason for going with a 50mm rifle scope? Is it really worth it? Will it help you shoot better?
     
  2. emmagator

    emmagator Well-Known Member

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    So basically tube diameter and glass quality are more important that objective size.
     
  3. Buano

    Buano Well-Known Member

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    The larger the objective lens, the more light a scope can let in. Mid-day a large objective lens doesn't help unless using extreme magnification, but a 50mm can give you another 20 minutes of shooting light at dawn & dusk & also helps in crappy weather, where there isn't much light to see by. Assuming the same glass quality, a 50 mm objective lens lets 56% more light through than a 40 mm lens. That's the reason people choose a 50 mm scope.

    The negatives of a large scope is easy: They are heavy & they cost more.

    Tube diameter limits range of adjustments but does little to improve visual quality.
     
  4. adam

    adam Well-Known Member

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    The best polish to the lens is also in the center... The larger the lens, the more probability you have of getting a lens with a nice big area with high resolution, diminishing at the edges. This will probably only mean anything to you if you are trying to get a value priced scope for a lesser used rifle...... The high dollar stuff had better come with better resolution than i can discern with my eyes.

    Resolution will also help you see later in the evening... lots of light will mean nothing if you cannot discern details.
     
  5. emmagator

    emmagator Well-Known Member

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    From reading around it seems that you have to have quality glass to transmit that light from the objective end to your eye. You could have a 40mm that transmits light well through the scope and a 50mm that gathers more light but doesnt transmit it to the eye well.
     
  6. J E Custom

    J E Custom Well-Known Member

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  7. 4xforfun

    4xforfun Well-Known Member

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    The only true test I have seen was a few years ago. I was was shooting a few rifles for some friends of mine. One had a Leuplod 4.5 - 14 x 40mm and the other a 4.5-14x 50mm. Both scopes were baught new that fall from Cabellas. It was PAINFULLY clear that the 50mm scope was far brighter in low light at the end of the day (when I like to do my shooting) than the 40mm. So much so that I actualy stopped shooting for the night and set the guns up side by side and just looked through them till DARK DARK. Now, during the day....same-same-same.

    Anyway, around here the best shooting is at/near dark. Probably everywhere, actualy. I have never baught anything but big objective lenses since, except for my match guns.
     
  8. Code4

    Code4 Well-Known Member

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    I'm going to take the cowards way out on this and basically sit on the fence.

    I beleive it is a balance. A balance between good glass, objective lens size and magnification.

    I have a Kahles AH 3.5-10x50 which is very bright when exterminating pests under a spotlight.
    My Zeiss Victory Diavari 2.5-10x42 has the best contrast at dawn and dusk.
    My Leupold 4.5-14x50LR allows plenty of adjustment and magnification for varminting.

    Each are very good but are mounted on different rifles for different applications.
     
  9. J E Custom

    J E Custom Well-Known Member

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    +1

    I totally agree

    Our Eyes also have an effect on total performance of any scope.

    J E CUSTOM