I have noticed with some of my cameras (especially with the m4/3 ones) that sometimes I get a better sharper image if I use it in portrait format. Not all the time but with certain lens it is the case. I tried to replicate this phenomenon on the Nex using the 30 f2.8 but it seems not to matter. I get the exact same crispness in landscape and portrait mode. Glad about that because it does have me thinking when using my m4/3 cameras.