@herf That's quite interesting, I figured it would be more linear. That's really nice to know looking at a 5500 lux sky during the day whether cloudy or blue will be more than enough to shift my schedule.
One more question, do our eyes need to be open to have a light response (I currently think it doesn't matter)? So if I stare at the sky with my eyes closed, will the schedule shift be the same as with them open?
I think this is an obvious one as if you could close your eyes to block out bright light responses then that would be more discussed.
Last question for this topic (so far anyway); What would be the most accessible (easy to purchase either in store or online) most stimulating indoor light that your aware of? Any style, any base etc, as I would like to replace two lights in a ceiling fan if they'll fit (max size is about a 26w cfl, but the socket will handle two 72w halogens).
I really appreciate all this information as I was thinking I needed over 50,000 lux during noon to really get my schedule in check. It's really nice to know that 1,000 lux early in the morning is plenty. On that note, maybe it's not all about schedule shifting. What about the part where not seeing enough bright light during the day affects how sensitive we will be to light after sundown--is 1-10 thousand lux still enough to mitigate those effects?