Quote Originally Posted by tufty View Post
Hi Ian,

A polariser is really only useful if you shoot in conditions where there is mirage,this appears in your spotting scope as a boiling effect as air rises on wet ground,the effect this has on the target is that it appears higher than it actually is so the shot goes high,a polariser negates this effect to some extent,it usually only occurs on open ground in sun
All a polariser does is reduce glare and improve contrast, it can do nothing to change the degree of apparent target movement caused by refraction (mirage). If you think about it, all you are doing is to alter what is perceived by the eye, you can do nothing to affect the conditions between sight and target that give rise to refraction. What you might achieve with a polariser is to reduce the apparent elongation of the aiming mark by virtue of the reduction on glare but you can do nothing about the refraction that occurs in the cylinder of air between you and the target. If anyone tells you differently, ask them to explain the physics that underpin their answer.


Rutty