EX1 WA lens + filter?
 

Is it possible to mount the Sony WA adapter with Tiffen T1 filter mounted on the EX1?

Not possible:

Not enough space between the IR filter front end with the glass at the back end of the WA adaptor, you’ll end up cracking the IR filter and damaging the WA glass.
I don’t think it’s even possible to fit an IR in front of the WA lens, the moulded sunshade and lack of screw thread prevents anything from going on.
One of the annoying draw backs of the EX1/3.
Maybe somebody out there has a work around (Centaury optics)??

Andreas