Yes you can!
its a bit unnecessary optical resolution but the SD image will only look the same or better.
especially at the end of the zoom range and the sides of a wide-angle there will be quite some improvement over an SD lens.
I sold off my SD's and use the HD for all my jobs. no problem.
And SD wide angles are worth good money still.
Thomas Kist
Freelance D.o.P
Amsterdam,The Netherlands
PDW-700,EX-3&Letus,FCP 6
http://www.thomaskist.com