Rediscover - Understanding Mirror Lock-Up

Understanding Mirror Lock-Up
Techniques for Reducing Vibration
The greatest enemy of image sharpness is vibration. One of the best ways of beating vibration is through the use of mirror lock-up (MLU). But, there is a range of tools and techniques involved in achieving the sharpest possible images, and we'll look at each of them in detail.
The Weakest Link
Let's look at the things that happen when you take a photograph with an SLR;

— the mirror flips up
— the aperture closes to the predetermined F stop
— the shutter opens for the pre-determined amount of time
— the film or sensor is exposed to light
— the shutter closes
— the aperture returns to wide-open for viewing
— the mirror returns to the viewing position

The items above that are in red happen before the film or sensor is exposed, and therefore can each contribute to image unsharpness. The items in green happen after the exposure takes place and therefore have no effect on image sharpness (unless shots are being taken in rapid s...