Doug Kerr
Well-known member
My Canon EF 50mm f/1.4 USM lens has always had a substantial amount of "lost motion" in the operation of the manual focusing ring. It occurs with the AF/MF switch in either position.
Here's the scenario.
There is some dispute as to whether this is an inherent side effect of the very peculiar full-time manual focus mechanism used only in this lens, or if my copy just has some defect.
Could those having this lens take a minute to see if they work that way? It does not even need to be on a camera to check this.
Thanks.
Best regards,
Doug
Here's the scenario.
The camera is trained on an object well within the focusing range. The current focus setting of the lens is beyond the subject distance.
While watching the image in Live View, I turn the focusing ring in the "near" direction to being the object into focus, but I go a little too far.
So I reverse the direction in which I turn the ring, now to the "far" direction. But the ring moves quite a way (about 1.5 ribs on the rubber tire, or about 4.5°) before I see either any movement of the distance indicator or any change in the focus state of the image.
Then, after this "lost motion" is taken up, I see the distance scale begin to move in the "far" direction, and the image begins to change accordingly.
While watching the image in Live View, I turn the focusing ring in the "near" direction to being the object into focus, but I go a little too far.
So I reverse the direction in which I turn the ring, now to the "far" direction. But the ring moves quite a way (about 1.5 ribs on the rubber tire, or about 4.5°) before I see either any movement of the distance indicator or any change in the focus state of the image.
Then, after this "lost motion" is taken up, I see the distance scale begin to move in the "far" direction, and the image begins to change accordingly.
There is some dispute as to whether this is an inherent side effect of the very peculiar full-time manual focus mechanism used only in this lens, or if my copy just has some defect.
Could those having this lens take a minute to see if they work that way? It does not even need to be on a camera to check this.
Thanks.
Best regards,
Doug