x20 objective lens from leupold
- Thread starter evolture
- Start date
Pros: Allows very low mounting, may allow for more latitude in fore-and-aft placement to effective use eye relief, decreases weight, and just plain looks good on a big-bore rifle.
Cons: With everything else being equal (which it never is) it delivers a dimmer image in low light with anything other than a very low magnification (4x or less, depending on your eyes).
I don't generally shoot long distances or use many high-velocity chamberings. For my usage, the Leupold 1-4x and 1.5-5x scopes, both with 20mm objectives, are my favourite scopes...I've probably got a dozen, and never pass up a good deal on another one.
John
Cons: With everything else being equal (which it never is) it delivers a dimmer image in low light with anything other than a very low magnification (4x or less, depending on your eyes).
I don't generally shoot long distances or use many high-velocity chamberings. For my usage, the Leupold 1-4x and 1.5-5x scopes, both with 20mm objectives, are my favourite scopes...I've probably got a dozen, and never pass up a good deal on another one.
John
The main advantage is a lighter and more compact scope. The disadvantage is that light-gathering properties may be diminished at higher magnifications. This is a function of exit pupil, which is objective lens diameter divided by magnification. The pupil diameter of your eye in a given condition is the largest exit pupil you can make use of; anything larger is of no benefit. Average maximum pupil dilation is 5-7mm with a daylight diameter of 4mm
For a 20mm objective, exit pupil works out to 5mm at 4x. This will provide good light transmission for most users in most conditions. Moving the magnification up to 5x shrinks the exit pupil to 4mm; still optimum for most users in broad daylight, but with slightly diminished performance in low light conditions.
For a 20mm objective, exit pupil works out to 5mm at 4x. This will provide good light transmission for most users in most conditions. Moving the magnification up to 5x shrinks the exit pupil to 4mm; still optimum for most users in broad daylight, but with slightly diminished performance in low light conditions.
