Hello Yoshihiko :) This shot is actual a manual blend of (3) bracketed images each taken @ ISO 100, F16. This almost could have been done with one image but unfortunately the dynamic range of the scene was just a little too much for my camera to handle. I had to use a little bit from the overexposed image to bring back some detail in the shadows and a little from the under exposed image to bring back some detail in the highlights. Essentially in the 'properly' exposed image the darker trees you see were almost black and the clouds in the central part of the sky were blown out. Hope this helps :)

Thanks Miles...believe it or not the water level was actually quite a bit lower than this when I visited around 3 weeks later (ref. my image Sparks Lake Sunrise). I had always seen images of this lake with the trees out in the middle surrounded by water so it definitely caught me off guard when I saw the water level so low.