Quote Originally Posted by Jonathan Huyer


Oh I'm a big fan of these filters. I also follow the Singh-Ray blog which is really good:
[url="http://singhray.blogspot.com/]http://singhray.blogspot.com/[/url]
I own the Vari-ND duo, which is a combo polarizer and ND filter that is adjustable up to 8 stops darkness. It is rather thick so I can't use it below 35 mm focal length on my full-frame camera without vignetting. I also have a few of their 'Galen Rowell' ND grads, in 4x6 format. These are my favourite by far. Yes they are all rather pricey... I can't understand how they can charge that much for a piece of smoked plastic, but they sure work and there is zero distortion, even when you stack them.
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Does autofocus work adequately with the Vari-ND duo on? I have a Fader ND Mark II and the camera never seems to nail autofocus when using the filter (I'm using it with portraiture...so a "little bit off" is quite noticeable. The following shot was taken using manual focus and live view:





Canon 7D, 85mm f/1.8 -- f/2, 1/200, ISO 100