I was out this evening with the flintlock, quitting time 5:42. At 5:10 I thought to look through my sights, rear aperture, front black blade. I had to wave the rifle about to finally find the front sight, and the rear sight was as blurry as it could get. I packed up and headed out. It was still very bright out of the woods.
I tried some masking tape on the front and rear when I got home, and it showed well, but recreating the lighting I was experiencing earlier in the woods, I'm not sure.