F-number lengths. Therefore, reduced–depth-of-field effects will require smaller f-numbers when using small-format cameras than when using larger-format cameras. Image sharpness is related to f/number through two different optical effects: aberration, due to imperfect lens design, and diffraction which is due to the wave nature of light. The blur optimal f-stop varies with the lens design. For modern standard lenses having 6 or 7 elements, the sharpest image is often obtained around 5.6–8, while for older standard lenses having only 4 elements (Tessar formula) stopping to 11 will give the sharpest image. The larger number of elements in modern lenses allow the
Opposite lock Left-foot braking is the favoured technique for using opposite lock in a front drive vehicle. Opposite lock can be a useful technique for saving a car from a loss of control such as an unintentional skid. A related technique is the handbrake turn, in which the rear wheels are deliberately locked in order to break the friction between the tires and the road, allowing the car to be spun around a very tight bend or junction, etc. Opposite lock Opposite lock, also commonly known as counter-steering, is a colloquial term used to mean the steering associated with the deliberate use