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Message: <blockquote data-quote="Kevin Purcell" data-source="post: 1402037" data-attributes="member: 68323">The aperture makes no difference as the brightness I measured in daylight (the measuring area I'm in has windows on two sides a couple of feet away with sun coming in one window). My eye's pupil is smaller than the exit pupil of both bins. So it's only the bin's transmission that makes a difference to perceived brightness in this case.I never considered the HS a particularly bright bin either but there you go. The differences aren't huge but pretty clear bin to bin except perhaps the ZRS/Diamondback ... they're pretty close and I wonder how the color bias plays on perceived brightness (blue vs greenish/yellow).Oh and the numbers on the second list are messed up. I'll fix that.Line up a bunch of bins and try it and you get a result. It may not be the one you thought you might get <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite2" alt=";)" title="Wink    ;)" loading="lazy" data-shortname=";)" />Then post it!</blockquote>