Sunflower

This is my first successful HDR radiograph. The sunflower is a little past prime but it was the right subject to test the proof of concept for HDR radiograph. The center is many times more radio-opaque than the petals so we did multiple exposures. My previous attempts at multiple exposures were unsuccessful as I did not realize that the energy level of the ray is not in a linear relationship with the kV setting on the machine. After doing multiple exposures on this flower, I think its more of an exponential relationship. This is a blend of two images at 26kV and 40kV on the mammo machine. The 40kV image only show the center with the rest of the flower virtually black. HDR blending in PS, vivezia 2.

Positive version available (click view larger version).