Originally Posted by SHRTSHTR
There is not a big advantage going to the 56mm.
The average size of a human’s eye pupil at night is 7 mm and in daylight it is about 4mm on average. If the optic give you a 7mm of exit pupil and you are using it for day use more than half the light will not reach the retina. I have also noticed if you are getting too much light and you look away you see light spots were ever you look and the targets look washedout. On a lot of my scopes I use a light reducer so I do not get the light spots and the washout is not there.
Size of bell divided by magnification = exitpupil. Hare are some examples.
The sweet spots for the 56 and the 50mm at Night and Day use.
50/7.14x = 7mm night use and for day use 50/12.5x = 4mm
56/8x = 7mm night use and for day use 56/14x = 4mm
You are really not getting much advantage over the 50mm. I feel there is a bigger disadvantage and that is you have to go with tall rings 1.00” at the low to 1.25” were the 50mm you can do 0.885”.
Mike @ CSGW