Dr Klaus Schmitt
Well-known member
Scorpio Supermoon shot in UV light
That does not look edible any more! Give me back my Swiss cheese moon!
Asher
Doug,
If the distance to the sun is reduced at any time, then, (if somehow we could distinguish this change), the moon will appear brighter, no matter where it is. The question is not whether or not we could measure that difference, (because I would wager that we could), but whether our eyes could distinguish the minute change.
Hi, Asher,
Well, the distance from the sun to the moon does vary, cyclically. Considering when the moon is in the "full moon" phase (when we see essentially its full disk), its distance from the sun varies from about 146.4 M km to 152.4 M km.
In that case, we can expect that the difference in the moon's luminance over this cycle is about 1:1.070; that is, at its greatest it is about 7% greater than at its least. In photographic terms, that is about 0.1 stop.
I'm sure that could be quite readily measured (and I'm sure has been).
Note that the luminance as we see it is also affected by atmospheric absorption, which among other things is affected by the altitude of the moon.
Even if we were able to have both moons present side by side, could we distinguish that difference? Not likely. We certainly would have no awareness of that change during the actual "cycle".
@Doug,
So it's about 0.1 of a stop; not much at all! But if one views only the brightest section of the gray scale, one should be spreading out our light perception over a much narrow range of brightness.
Do we know the limits of our ability to reset the range of the numbers of shades of light qe can distinguish?
Gorgeous.
If I was a moth I'd be flying there now.
Can I ask which lens you used?