D 146 - Dandelions O.M.G.

I spotted this field while on a short bike trip, then I fetched my camera and went back to get the photo.

Equipment

E-510 with ZD4015 (a strange lens for such a shot, I know).
RAW file developed in Lightroom: red filter, stronger contrast, sharpening.

What I learned

I was without a tripod and day was rather cloudy, so at f/16 and 40mm (80mm after crop) I wasn't able to get this sharp as I went down to 1/6 exposure time. In effect, the trees on horizon and the rock and the first row of dandelions are slightly out of focus.
I do tend to neglect the fact how much longer I need to expose to get proper photos at small apertures. Tripod isn't that heavy, is it?

If I used wider lens, than the DOF would get bigger and the trees on horizon would become apparently smaller, but the rock would grow too big.