[jarimakila]

My Tamron 70-200 shows the following problem:
- twist the lens slightly so that it moves in the mount
- as a result, aperture info stops showing in the display - you can take pictures, though
- twist it back and it's OK again
I have interpreted this as simply a mechanical tolerance, which leads to a contact break in the spring contact between the lens and the camera body.

Anybody else had similar problems?
I can live with this but have also considered Pentax purchasing 60-250. It's with WR and SDM but only f4.0 and quite expensive. The 300 mm SDM would also be great but again not for free.

[ChooseAName]

My Tamron 70-200 shows the following problem:
- twist the lens slightly so that it moves in the mount
- as a result, aperture info stops showing in the display - you can take pictures, though
- twist it back and it's OK again
I have interpreted this as simply a mechanical tolerance, which leads to a contact break in the spring contact between the lens and the camera body.

Anybody else had similar problems?
I can live with this but have also considered Pentax purchasing 60-250. It's with WR and SDM but only f4.0 and quite expensive. The 300 mm SDM would also be great but again not for free.

My copy of this lens jiggles in the circular vector of motion (as opposed to radial), i.e. it twists a little bit. I do not get the problem that you get though - operation of my copy has been flawless. Perhaps this is some sort of design flaw where you happened to get one that was just out of tolerance, and I happened to get one that was within.

[jarimakila]

You're probably right. I tested many of my other lenses similarly for mechanical tightness on my K-5 and there is always some room to play but the tolerances seem to be tighter. However, my only other bigger lens is the 50-135 SDM which is weather sealed.

[crewl1]

Solved: