Is there a website showing the cross section of a modern autofocuslens and how the autofocus mechanism in a lens works?

wrote:
Just curious to know how the lens barrel is moving up or down when you
press the camera's button. It must drain a lot of energy from the
battery to do this. I recall the old autofocus lens was a monster
size. Is there a diagram somewhere in the web which shows how this is
accomplished? Is there some kind of a spiral screw along the outer
skin of the lens barrel? I also assume that the bigger the lens, the
more energy needed to move the lens during autofocusing.
Thanks for the info.


I have seen such diagrams, but do not have a reference to any right now.
Consider too that it is not unique to autofocus. Remember that when
you do manual focus you only move one ring, you do not have to move
individual elements. Yes, frequently the mechanism employs a coarse
pitch helical groove or "thread". Consider that a small motor could be
geared down to move the focusing ring.

Most lenses are pretty well made these days with high precision and so
very little friction. As a result they do not take a LOT of energy, but
they certainly do take some. As a result, some camera manuals do say
that using manual focus, if available, will lead to longer battery life.