First a confession. I got serious about photography about 40 yrs ago with my canon Ftb. I am quite new to digital photography. (yeah, I know, what an idiot I laid off serious photography for most of the last 25 yrs. One thing that is amazing to me is that the new SLR cameras have lenses that only have aperture choices of 3.5 to 5.6??? My Ftb had a 1.4 to 22 range. Now that gives you control over your depth of field! Is it because of the speed you can shoot at with these new cameras? I see where you can set the ASA at speeds of over 6400 (wow). Anyway I was curious as to the limitations of today's lenses