Eye Pocket (forgivingness)

Discussion in 'Practical Long-Range Rifle Shooting' started by strow, Sep 11, 2012.

  1. strow New Member

    What determines “eye pocket” and its forgiveness?

    I assume objective diameter and magnification, but what else?

    What are some scopes that tend to have a large eye pockets and what are some that do not?
  2. Zak Smith Operations

    • Instructor
    Zak Smith

    The first parameter to look at is the diameter of the exit pupil (at the magnification setting). The second part of the "eye box" is how far forward or backward you can be from the "optimal eye relief" distance and still have a good sight picture. I haven't been able to find any published parameters regarding this second one; however, conceptually it should relate to the angle the light rays travel as they exit the ocular lens and enter your eye.

    For both of these, getting the right "rifle fit" is critically important to getting the most out of your eye box (and reducing parallax error). When you get in to a proper and relaxed prone position on the rifle, your eye should be in the center of the eye box, and you should not need any neck strain to keep you there.

    Scopes known for flexible or large eye boxes: S&B, Hensoldt
    Scopes known for smaller or less flexible eye boxes: Nightforce, USO, Leupold

    There is a correlation of the ratio of objective lens size divided by the magnification to the size of the exit pupil.

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