As for the blurriness…
open your DV quicktime into quicktime player. You need quicktime pro in order to do this.
go to window menu>show movie properties (apple-J)
then select the video track and click on the visual settings tab.
there will then be a check box in the lower right that says “high quality” make sure it is enabled.
this should now make the video nice and crisp.
As for the Black Magic DV encoder, I’m not so sure about that .
good luck
m