Photoclubalpha

This is repost from dpreview.com - sorry if this is redundant for anyone:

I just purchased a Tamron 70-300mm lens to use with my A300. I was able to give the lens a good workout at the zoo this past weekend and every seemed in order, except for one thing.

When the AF reaches it's limits (either infinity or on the close end) it doesn't cleanly stop. Rather, I feel if the AF motor is kind of forcing the last 1/10th of a degree rotation. So much so that one of the plastic rings surround the lens flexs a bit, and the barrel of the lens shifts slighly. Is this normal?

I'm just entering the world of DSLR photography and don't have much to compare this lens to. Is this something I should expect from a budget lens? Is this going to cause problems with my camera body (or the AF motor)?
Thanks in advance for any insight!

Jake

Two points:

1- Welcome to this forum

2- IMHO, I think the problem lies in the contacts. The lens is not sending info to the camera so the motor stops. And it would be best to either change the lens (if under warranty) or send it for repair.

Thank you for your quick response - that was my uneducated suspicion as well.

Also, I'm glad to be on the forums - I'm hoping to learn as much as I can.

Cheers,

Jake

Tamrons have a six-year warranty and that is not normal behaviour - as suggested, angle for a replacement.

David