Severe Vignetting with DOF adapter!

[elclanrs]

Now that I've time I'm testing my new CAMs static dof adapter with a Canon EF 50mm 1.8 lens and I'm having problems with really noticeable vignetting. I'm pretty new to the DOF dapater world so do you know any tips to reduce vignetting? Is zooming in a bit the solution? I've read that a macro lens attached to the Canon EF lens might reduce vignetting too. My cam is a Canon HG10.

Oh, and how do I clean the dust particles? I think a blower might do it...