I understand better coatings promote more light transfer in optics and I understand exit pupil. Let's take a 2-8x32 variable power rifle scope that the manufacture specifies their coatings allow 94% light transmission.
On 2x, there would be an exit pupil of 16mm - can I assume the coatings would transmit 94% of the light entering the objective?
On 8x, there would be an exit pupil of 4mm - what percent of light would be transmitted? Thanks.
Coatings in no way over shadow an increase in light grasp. Going from the long-time industry standard magnesium fluoride coatings to multi-coatings, you can, in theory, gain ~ 13 percentage points in light transmission.
When trying to discuss the difference in multi-coatings from one quality manufacturer to another you are splitting hairs with an axe—it’s pure folly.
That folly will, however, take up thousands of words, over several days, several times a year.
Most people don’t consider the mathematical differences they speak of are well below their personal threshold of recognition, or that the difference they are seeing is really the result of:
baffling, blackening of edges, size of field stops, position of field stops, knife edge on field stops, slotted or non-slotted prisms, design of the eyepiece, number of elements in the eyepiece, etc.
But then, over the years I have learned that when it comes to discussing optical performance: if the observer doesn’t know the source of a particular malady, he will eagerly shift the blame to some potential cause that he IS aware of.
Correct? No. Handy? Yes. :cat:
Cheers,
Bill