For most work I want a camera with DoF preview, but for broad landscapes and street I don't really need it. The Super just grew on me, though I would never keep it instead of the MX, LX, or other camera with DoF preview, plus other things like interchangeable focusing screens. On rare occasion, I do want to check DoF with the Super, so I press in the lens release button and rotate the lens like I'm taking it off until the diaphragm closes. After I check I just turn the lens back until it locks. It's funky but it works. The lens has a ways more to go until it could fall off, so being reasonably careful there's no problem.