The gear I had that fit is for "Canon EF16-35mm F 2.8L USM zoom gear". I placed a wide rubber band on 17-70 barrel and the gear snugged up very well. On another note what extension ring are you using, the 40? I stacked 2 sx rings and the lens just touches the inside of glass at 70.
Does anyone know what S&S zoom gear fits the new HSM version of this lens? I'm thinking of setting it up in an RDX housing with the FE dome port. Since it's internal focusing now I don't think you'd really need an ext ring...?
Jack
