How's the flare control on this lens? Is a hood needed? I'll be picking up this lens t'rrow: I checked out the lens hood - it's price a rip-off. But, if need be, I'll get one (of course, this would kill the portability of the lens). I have a Panasonic 20/1.7 and it hardly flares. So, I've been using it without a hood and would like to do the same with the 17/1.8. Thanks.