So I'm playing with aperture and I took 4 photos with the EOS set on manual aperture so I can learn how aperture affects the pictures. Each time I took one of the 4 photos, I increase the aperture. I then brought the pictures into picasa so I can look at the data and compare the pictures. I get this for the 4 photos: f/3.5 f/5.0 f/16.0 f/22.0 But if I look at my lens (which is the one that came with the camera) it says: 200mm EF-S 18-55mm 1:3.5 5.6 So if the aperture of this lens stops at 5.6, how did I get the camera to take a picture at an aperture of 22.0? Sorry if this is so basic. Thanks.