Canon EOS50D EOS 50D Instruction Manual - Page 180

3 Custom Function SettingsN C.Fn III -6 Mirror lockup 0: Disable 1: Enable Prevents camera vibrations caused by the reflex mirror action which can disturb shooting with super telephoto lenses or close-up (macro) shooting. See page 106 for the mirror lockup procedure. C.Fn III -7 AF Microadjustment Normally, this adjustment is not required. Do this adjustment only if necessary. Note that doing this adjustment may prevent correct focusing from being achieved. AF adjustment cannot be done during Live View shooting in Live and Liveu modes. You can make fine adjustments for the AF's point of focus. It can be adjusted in ±20 steps (-: Forward / +: Backward). The adjustment amount of one step varies depending on the maximum aperture of the lens. Adjust, shoot (73), and check the focus. Repeat to adjust the AF's point of focus. With setting 1 or 2 selected, press the button to view the register screen. To cancel all the registered adjustments, press the button. 0: Disable 1: Adjust all by same amount The same adjustment amount is applied to all lenses. 2: Adjust by lens An adjustment can be set individually for any particular lens. Adjustments for up to 20 lenses can be registered in the camera. When a lens whose focus adjustment has been registered is attached to the camera, its point of focus will be shifted accordingly. If adjustments for 20 lenses have already been registered and you want to register an adjustment for another lens, select a lens whose adjustment can be overwritten or deleted. 180