Excerpt: I am sorry to say that, after testing it, I have to say that I will not recommend at all this product as it is nearly useless because in most circumstances has a very noticeable vignetting in a cross pattern that is not possible to be corrected by photoshop.
Excerpt: It's nice and clear, and I can't really see any distortion (if there really is any). The construction feels solid, and the ring is smooth. I'm using it on a Sigma Art 35mm 1.4 with my A7s, so, without it, I really can't shoot SLOG2 during the day.
Pros: Clear Optics, Easy To Use, Strong Construction
Excerpt: This is a good variable ND filter, assuming you mind teh standard advice about not using the darkest setting. The biggest drawback is that it has no front filter threads, so you can use filter stack caps for carrying it.
Excerpt: I think this is a very high quality product. What drives me nuts is that there are no threads on the outside of the filter. I can't use stack caps and the lens cover won't stay on with this filter on the lens.
Pros: Clear Optics, Firm Mount, Strong Construction
Excerpt: I use this on my Sigma 35mm 1.4 and it worked great. The stop down allowed me to use my Elinchroms, shooting in low F values while in bright Florida sun with fantastic results. This filter was easy to use and I saw little to no sign of quality loss.
Excerpt: The filter is easily installed and unlike other filters, it doesn't "wobble" after it is installed. It turns easily and slides without a hitch.The glass is of high quality and colors don't suffer when using it.
Pros: Clear Optics, Easy To Use, Firm Mount, Strong Construction