For me, the mechanical of HD is not sufficient, the two that I held in my hands, had a lot of game in the shooting script.
The Pro1 Digital is here much better processed / constructed. With my preferred method: Geli screw threaded on the polarizing filter and then turn the lens hood, is the Hoya HD very spongy / rickety :-(
It also impressed with my two copies, in contrast to the Pro1 that they are very sensitive to backlight. I could see clear reflections (flares) on many of my pictures.
Therefore, my recommendation is clearly Hoya Pro1 Digital, especially since he is also much cheaper!
1 star deduction for the non-optimum mechanical quality and one for the backlight sensitivity.
