Alex wrote:Thanks for explanations guys. I would have thought that MLU would be unnecessary with a good tripod.
Not really; the physical handling of the camera can still induce some vibration into the setup. The idea of MLU is to try to remove any and all movement from the situation before opening the shutter.
Killakoala correctly points out that the effects of camera movement are exaggerated when using a long lens (hence VR technology) and so MLU can be very useful under those conditions.
And Philip, yes, it did. Sort of. The way that worked was that the mirror flipped up before the first exposure was made, then all exposures were made, then the mirror was released. But that wasn't really an MLU function per se, it was just the way the camera worked, and from an engireening perspective, it was a simple but logical way to improve the available FPS.
For those who are interested, the way it worked on many older (mechanical) Nikon film cameras is that when you engaged the self-tiimer, the mirror would flip up as you pressed the the shutter release button. With a (typical) 10 second delay, the camera then would have those 10 seconds available to settle, before opening the shutter.
The mnirror would return to its normal at-rest position upon completion of the exposure.