Eye Focus in Portrait Photography

Don't lengthen the focal length and focus again! For the method of lengthening the focal length, it is sometimes far away from the portrait, but the focus is too large to aim at the eyes accurately, so there is a saying that the focal length is lengthened and then pulled back to shoot. This method has no problem in theory, because the distance from the focal plane to the fuselage is constant while changing the focal length, so in theory, the focal point is locked and zoomed after lengthening the focal length, so there will be no defocusing phenomenon, but it is difficult for us to control the camera without zooming before and after the hand-held shooting. . . In my opinion, don't lengthen the focal length to focus. If your portrait is far away from the machine, the depth of field will be larger because of the large object distance. Even if you can't focus on your eyes accurately, as long as you focus on your face, your eyes will be clear because they are within the depth of field and range. . . As for the composition after focusing, this is also a truth. If your depth of field is very small, you should focus on the composition. If the camera moves back and forth carelessly, virtual focus will appear, which is not recommended.

When zooming, if your exposure is locked, the exposure value is constant and is not affected by zooming. . If the focus is locked, the distance between the focal plane and the camera is constant and is not affected by zooming.