Thanks to cameraland.nl I got the opportunity to test the Rodenstock Vario ND filter, a variable neutral density filter. Last year I got my hands on the LCW Fader ND mkII for a test (click here to see the results). Personally I was not very impressed by the LCW Fader ND, not even by the mkII. My main concern was the ‘cross’ (cruciform or ‘X’) the would show while using a wide angle lens. It appeared on my Canon EF 24-70mm f/2.8 USM so I didn’t even bother to test the Canon 16-35mm f/2.8 USM II. (See on the example of the cross issue on this page.) So I was hoping the Rodenstock Vario ND will perform better.
The first difference that I noticed was that the product description of the Rodenstock Vario ND was pretty clear on the ‘known’ issues with wide angle lenses. They even marked the filter with ‘max’ which is just next to the +5 marker. Anything beyond this max marker is not guaranteed to give good results. And they were right. If you ignore their warning you will get unexpected results as you will see in my tests. I didn’t really experience any issues with color shifts, so that is way better compared tot the LCW Fader ND mkII. With the lather I experienced color shifts on several occasions.
With the filter from Rodenstock I decided to give it al full test. I tried it on almost every piece of glass that I own. This caused a few problems due to the fact that I got the 82mm version of the Rodenstock Vario ND for my test and most of my lenses have the 77mm thread. So I needed an adapter ring. Normally this wouldn’t be a problem but this time