OMG...tell me thiis guy is wrong about micro four thirds

Moti wrote:

That is a very precise and correct explanation but it is only academic. On the practical side of real world photography, it doesn't work that way.

As a photographer, i decide upon the amount of DOF I need to get and I can control that by chosing the right tools, dialing in the correct the settings and using proper techniques. That is all.

Now let's assume I have an assignment and I need a shallow DOF. I prefer to take the FF for the job, because it has a larger sensor, allowing me to get better dof control for a given focal length. I totally agree to your theory but for me, it translate to sensor size. If I need a shallow DOF, I'll choose a FF because the larger sensor size will give me some advantages compared to a smaller sensor. In other words, sensor size matters.

Now that I have chosen the camera, I have to choose a lens. Again I general theory you may be right, but practically, for a given camera body, which is where I am now, the focal length of the lens does play an important role. On my chosen body, I'll get a shallower DOF with a 100mm than with a 50mm and that is a non disputable fact. In other words, focal length does effect DOF.

Now I have my gear ready and go for the settings. I agree that thaoretically, DOF is controlled by diameter of the aperture but I couldn't care less because when I am shooting, I do not have a tape measure with me and on my camera, there is no indication for aperture diameter.

So for a photographer, all that translates to F stops because this is the only equivalent indication we have on our cameras.

In other words, the paremeter used by photographers as an indication for DOF control is F stop and not aperture diameter.

Of course, you were also right about the subject distance but to be precise, it is the relation between the camera to subject and the subject to background distances that counts.

To sum up, as a theoretician, you were right.