Variable ND filters

[Birk]

In the past I tried using a variable ND filter on another mirrorless camera and it resulted in some strange shading of the image. I returned that filter . Is this effect common to mirrorless cameras ? I have used standard ND filters with no problem. Please reply if you have used a VND filter on a Sony camera and tell me what was the result . Thank you

[dbvanhorn]

According to the docs on my Hoya filter, if you go too far in the dark or light direction, or your FL is too short, you will get this.

The Hoya has marks that show how far you can go before the problem happens.

[dmcgrew]

I recently purchased the Polar Pro variable ND filters.. they are awesome. No weird vignetting at all. Super nice case too.