In my night-time tests on a black-and-white chart, which I've been making for at least a decade now, several scopes have tied for the highest brightness rating of 8. The test is set up to remove objective size from the factors.
How do you eliminate objective size from the factors affecting brightness? I can see equalizing the objective size where possible, but removal? Some of those Zeiss monsters are for all intents and purposes a spotting scope with an included reticle.
I can't speak for MILES58; but, I speculate, to be fair, one has to equalize the criteria by utilization of identical exit pupils. Thus a 50mm objective at 10 power (exit pupil of 5) could be fairly evaluated agains a 40mm objective at 8 power (exit pupil of 5). This is just my speculation as to what is meant by removal of objective size from the factors. I may be wrong. If you don't believe me, just ask the homunculus from Alaska.
