Canon EOS R6 Advanced User Guide - Page 105

Depth-of-Field Preview Press the depth-of-field preview button to stop down the lens to the current aperture value setting and check the area in focus (depth of field). Note The larger the aperture value, the wider the area in focus, from the foreground to the background. The depth-of-field effect is readily apparent on images as you change the aperture value and press the depth-of-field preview button. Exposure is locked (AE lock) as you hold down the depth-of-field preview button. 105