For Earth Day, we participated in the 8:30-9:30 pm "lights out," getting by with two candles, the occasional cell phone screen or pocket flashlight.
I dismantled yesterday's Czech bridge & put stones back in box according to the packing plan. I think it would have taken more candles to actually build something.
Then I did some construction with Froebel Gift #3 blocks. That worked, even though the candle wasn't very close.
I spent the rest of the hour taking pictures with only candlelight illumination. The shutter speed was 15 seconds, handheld. It turned out the biggest problem was lack of contrast - particularly the lack of shadows.
I could have gotten a better picture by moving the nearer candle down from the mantle to sit on a book or two next to my construction. But then, that wasn't the point.
Maybe the point was that you don't need a lot of light to have good block play.