Debi Prather , Mar 10, 2009; 10:00 a.m.
Per Tamron the correct filter size for this lens is 62 mm, but after purchasing a CP 62mm, I find I cannot just screw it on to the end of the lens - do I need an adapter (and if so, what is it called?), or am I doing something wrong?
Thanks
Debi
Rainer T 
, Mar 10, 2009; 10:33 a.m.
I assume this is the 18-250mm ... in that case, yes, the filter size is 62mm, and a normal 62mm CP should fit.
Just a note ... CP "circular polariser" ... polarisers are filters that are intended to be rotatable when mounted on the lens ... you have to grab the polariser on that part which is connected to the thread (which goes on the lens) ... not on that side which will take the lenscap.
If you touch the filter on the wrong spot/side, the only thing happening is that the polariser itself rotates, while the thread of the filter does not rotate, and therefore does not screw into the lens.
Jeff Hammond , Mar 10, 2009; 11:39 a.m.
Hi Debi,
The filter threads are very fine and occasionally don't line up very easily in my experience. Be patient, make sure that the filter is properly aligned to the lens, and don't use too much pressure on the filter as it can be relatively easy to cross thread the filter into the end of the lens.
Good luck!
Don Peterson , Mar 10, 2009; 05:29 p.m.
Debi-when using the polarizing filter,try to get in the habit of turning it counter-clockwise when using it, otherwise it is very easy to unscrew it and drop it.
