If you happen to have the X100S and the tele-extender for it you really have to remember something. I went to a museum in Frankfurt where all of the images in last few posts were taken. Going out the door I had the extender on it and as I thought a 50mm lens would be fine for the museum. When I got there I decided that a 50mm was too long so I took off the extender making the lens a 35mm. Back to normal so to speak. What I forgot to do was change the menu back to a 35mm, i.e. I didn't tell the camera that the extender was not in use. Now looking through the viewfinder, you don't notice a thing but the camera still thinks the extender is on and applies the software correction to the images. As I got home and looked at the images on my workstation I nearly fell off my chair and couldn't believe at how stupid I was. If you haven't seen the distortion correction in use you may want to try it out, it's horrendous. I bet after you see the distortion, you will never again forget to change the menu ever again.
I know I won't. It took me ages to correct the images again manually, and you can still see the effects on some of the images. I'm still impressed with how good the images are from this Fujifilm camera. I know there's a new model out there, but the X100S is fine for me.