5d mark iii next to a Sony NEX-7??? Image quality.

Hi all,

I recently purchased the Sony Nex-7 with the Zeiss 24/1.8 lens and I'm very impressed with the results. I wanted a smaller camera that I can easily take with my on trip opposed to a bigger SLR.

I'm still tempted to buy the 5d Mark iii as replacement for my ancient canon 20D. I'm sure the autofocus will be better on the 5d Mark iii but I'm curious on the image quality of the Nex7 - Zeiss combo compared to eg. 5d mark iii with a good L lens (24-70 or perhaps a prime).

Do you think the full frame 5d mark iii will be a step up in image quality compared to my smaller sensor Sony combo or will the improvement only be marginal?

Appreciate your feedback.