21Concepts in PhotographyWhat controls out-of-focus effects?DOF depends on aperture valueThe wider the aperture is (namely the lower the aperture value), the lowerthe DOF becomes. Under the condition where the focal length is equal, alow aperture value leads to a photo with a low DOF.27 mm F3.5 27 mm F11DOF depends on focal lengthThe longer the focal length is, the lower the DOF gets.9 mm angle27 mm angle
