do you actually adjust the fstop on the lens. Until just recently, the only adjustments on the cameras were the shutter speed and ASA (ISO) adjustment.
With the advent of auto-focus and digital SLR's adjusting the aperture on a lens sometimes could cause a conflict with the auto-focus process ... the photographers big paw interfering with the lens as it attempted to focus.
Some of us pros use cameras that still allow the photographer to use manual focusing techniques. The f-stop adjustment is actually in the lens. If you detach the lens from the camera body and then change the f-stop, you can look in the lens and see the aperture change. | 