E, the 6x42 will indeed gather and direct to your eye much more light energy than the 4x28, since it has a larger objective and the right magnification for low light scope exit pupil/eye entrance pupil match. The more energy in low light the better for the eye�s receptors to be activated in a useful way. That is no doubt. What if there is enough energy for the eye to see something in low light but due to aberrations the objects edge is not sharp enough to be distinguishable from the background? It�s easier to detect a shape in low light conditions when the edge has a sharper shade transition with respect to the background rather than the case were the shade transition is smoothed out by aberrations. It�s easier to detect a shade difference transition when its abrupt compared to the case of a little brighter object with a brighter background and a less abrupt transition. It�s human nature. To make an analogy, if you need to attract someone�s visual attention with a faint light from a distance, you rather strobe it than illuminate in a constant fashion�That�s why resolution is very important in low light, and to that respect in any light, vision When you claim than your 6x42 is better in low light than a VXIII with similar transmission, it�s not due to the 1% transmission difference but rather due to the probable higher resolution of the fixed scope lenses used�.even if they are not fully multicoated and index matched etc� Take two similar scopes and make a resolution test at day time. The one with more resolution will most likely outperform the other in low light even if that �other� has a 2-5% percentage point more transmission, a little larger objective etc�Try it with 2 of your scopes and see for yourself and let us know of your findings... Aic
