Hi All, So I recently bought a Oly 75mm f1.8 from a member on this site. It is a beautiful lens, and wow what a gorgeous front element! I only got to experiment with it a little over the weekend, but I think it will be a very nice addition to my kit. Anyway, while messing with it in my kitchen last night I noticed something odd. It seemed to be making a fast clicking noise just with me moving the camera around and not touching any buttons. What I found is that it was the aperture opening and closing. As I pointed the camera towards the light over the sink the aperture would close down, and as I pointed towards a darker area it would open up. I have never noticed this kind of behavior before with my lenses so I thought it was the new lens. However, after a bit of sleuthing I figured out that it was actually my Em-1 mark II. It seems that when you put it into manual focus mode it adjusts the aperture according to the available light. I've no idea why it does this in manual focus mode, but I am sure there is a reason. The other funny quirk is that it continues to do this even after you put the camera back into AF. But when I put the camera back into SAF +MF mode (my usual focussing mode), turned the camera off and back on the behavior stopped. Then no matter where the camera points the aperture remains wide open till you take the shot (this is what I deem normal behavior). I think it might have been due to the strong light difference in the overall low light of the kitchen last night vs the bright light over the sink. I wanted to verify that it was not the 75mm lens, so I tried several of my lenses and saw the exact same behavior. I even tried a few different lenses on my Em-1 mark I and found the same behavior. I think the only reason I actually noticed this is because those big ol' aperture blades on the 75 are a bit noisier than say my 12-40mm f2.8 pro. I don't really think its a problem since I never notice it before, and have been shooting with my Oly gear for several years now. I just though it was an odd little quirk that perhaps some of you might have noticed too.