Hi Caveman. This is a great shot.... wonderful perspective, dof and color. Outstanding clarity and focus. ... and you did so at 1600 iso. Amazing. My guess is you could possible have slowed the shutter speed down a little, hand held, at 12mm so you could have virtually the same exposure and aperture between iso 640 and 800. At those ISOs you could possible have achieved a little more saturated colors and less noise ( though I see no noticeable noise in this shot... could be you ps'd the noise out). Marvelous shot. All my best, Michael.
