<br />Thanks for the reply. <br /><br />FYI, I think that the lens is actually OK. <br /><br />I asked the guys in
Robert White in the UK about this. They had no 180mm SL in stock but they did go to the trouble to find another one and check it out for me. The 180mm SL lens they checked made a little noise too, when rotated. They also checked a 90mm lens and it was similar. <br /><br />So, I'm guessing that the sound is normal, probably made by some bearings rolling inside the lenses. Panic over. <br /><br />Thanks and regards,<br />Kieran<br /><br /><br /><br />