Thanks for that, I'm going to check there! I'm so excited about this lens now, another question, what is the difference then between an f2.8 and f4 lens (for example sony 70-200 f 2.8 and the beercan lens?) which would be a "better" lens? I've been taking pictures for quite some time but have never really stopped to learn what all the "lingo" means, so if you can explain it to me as simple as possible I would be forever appreciative.