I wouldn't have thought that the depth-of-field would change much between the 135 f3.5 and the 135 f2.8 but I find them worlds apart. It's much easier to nail the focus with the f3.5 lens. But when you do nail it with the f2.8 then it is very sharp and the rendition is great. I think the E-PL1 is one of the best cameras Olympus released in this category because I just like the images so much. Many will disagree with me on this point, but everyone is entitled to his / her opinion I suppose.