Variable ND Filters at 7 day shop - Talk Photography and Variable Neutral Density Filter problem: Open Talk Forum: Digital Photography Review. My comments have nthg to do with sunpro or other brands. Just sharing what I have came across.
Variable NDs are just 2 CPLs mounted together with 1 of the glass reversed. Not sure if you can imagine what I am talking about
I would suggest to get a fixed nd filter instead and it will depends on how bright the lighting is.