Interesting thing about the Sigma 24mm f1.8. They claim it will focus down to 7.1 inches. I find its more like 1.7 inches. Or as someone else said in a review, 'insanely close'. I don't know if this is a D300 phenomenon (doubt it), but as it does not AF on the d40x, I can't compare. I took this at night with no flash, will try something similar in daylight with more fstop to see if DOF remains funky when so close up.