Hi guys, got some really simple questions, hope someone can help me out.
1) I read that the f number is obtained from dividing the focal length of the lens by the physical aperture diameter, is that right? Does that mean that for lenses of the same focal length and same f number, the physical aperture size is the same?
2) Is DOF wholly determined by the physical size of the aperture, assuming that lens-to-subject distance and subject-to-background distances remain constant?
3) This one is related to qns 1 & 2. Say I use a 28-90 f4-5.6 lens and a 28-70 f2.8 lens, and take the same scene at 50mm f5.6 for both lenses. Will the DOF be the same for both pics?
T.I.A!
1) I read that the f number is obtained from dividing the focal length of the lens by the physical aperture diameter, is that right? Does that mean that for lenses of the same focal length and same f number, the physical aperture size is the same?
2) Is DOF wholly determined by the physical size of the aperture, assuming that lens-to-subject distance and subject-to-background distances remain constant?
3) This one is related to qns 1 & 2. Say I use a 28-90 f4-5.6 lens and a 28-70 f2.8 lens, and take the same scene at 50mm f5.6 for both lenses. Will the DOF be the same for both pics?
T.I.A!