Originally posted by osv when you can't move the camera you move the focus ring, not the aperture ring
You obviously live in a world different from ours, and just don't understand our world. In your world, cars come down a track very fast, but nature penalizes them if they vary from their chosen path. The rest of us have much less certainty in our lives.
For example, some years ago my daughter played basketball; all the adults loved to watch her because she put so much of herself into the game. Over time her knees starting bothering her, and the trainer, who was one of those adults who enjoyed watching her play, knew what the problem was without actually examining her knees. He gave her what she called "dorky volleyball kneepads", because he knew that whenever the officials sorted through a pile of players looking for the ball, they would find her at the bottom of it, and that constantly hitting the floor following the ball was her problem. When I took pictures of her, I zoomed back a bit because I wanted to show her in the context of her opposition, but if I had tried to photograph her tight up, I would have used a smallish aperture because I knew that when I took a picture of her, she would be nowhere close to where she had been when I focused the camera {and chimped to check on focus??}. That is exactly the problem the OP was asking about, and what most of us have been talking about all along. You have been in your own Sony world where "chimping" solves problems. Please write this down so you can remember it for a few seconds:
aperture ring does not change focus; it changes the amount of area seen by observers as being in focus, and thus protects from last second unexpected movement. Originally posted by osv i got "denial" because people in this thread don't know as much about cameras as they think they do; you certainly keep proving that, by constantly contradicting yourself.
Of course the theoretically perfect plane of focus has no depth; light rays are essentially radiation, that has no depth...
No! No! No!
You got denial because you insisted on using words indicating that "focus plane" has depth, that the area of perfect focus is more than a molecule thick. Even the words you quoted contradict you.
I have not contradicted myself - you have constantly misrepresented what I said.
The plane of focus having no depth has nothing to do with radiation or light waves; science takes its vocabulary, words and their meanings, from math, and the definition of plane says that a point has zero dimensions, a line has one dimension, a plane has two dimensions, and a solid has three dimensions.
That is why any plane, including a focus plane, has two dimensions.
I have taught at the college level off-and-on over the years. In teaching introductory courses, I have become more and more focused on vocabulary - can my students use a word correctly and do they understand correctly when someone else says something. You're not doing very well in either category.
Originally posted by osv you obviously never bothered to read the link, because you still think that focusing can be done with the aperture ring.
No, No, No
I have never said that.
Aperture narrows or widens the area of "acceptable focus"; some people use that to "isolate" the subject, while the OP wanted to go in the other direction to widen possibilities/options.
Originally posted by osv the claim was, that there is no such thing as a "plane of focus", and i proved that wrong with the zeiss link.
No! No! No!
The claim was that you were misusing the term, and your own article proved that you were.
Over and over you used words indicating confusion between "plane of focus" and DOF.