Just picked up a sigma 30. here is my question. when the lens is not mounted, or the lens is mounted with camera off, the aperture is closed, and as I tilt the lens, it makes a clicking sound like things are shifting inside, and I can actually feel thing tilting inside. when the lens is mounted and the aperture opens, the lens no longer makes the sound. Is this normal? has anyone else experience this? if the camera is on, and the aperture is closed down to f22, it still does not make any noise.
can someone who owns this lens test this and see if its normal? thanks.
kevindar wrote: . thanks. where does one go to find out about these "well known characteristics"? what happens trying to autofocus during video?
The two Sigma's I had, 30mm and 19mm, would both hunt and hun, seldom locking onto focus, when used in AF mode for Video on the NEX-7. I think most folks use those lenses in MF for video.
Both rattle, but 19 mm less. They're relatively inexpensive, but I wasn't sure about the long term effect of this internal knocking on performance and return both. I hate gear failures.
The 30 was nice. The 19 was unimpressive off center with poor corners.
. thanks. where does one go to find out about these "well known characteristics"? what happens trying to autofocus during video?