[frank]

I bought a set of 85x110mm Hitech GND filters and a P-typw Cokin filter holder. I found that the set does not work well on my AF-S 16-35mm F4 lens, which causes heavy dark shades from about 26mm downward. From the Cokin document I read that Cokin has a wide-angle holder but it appears that the wide-angle holder only works down to 20mm. According to the document, only the X-PRO series of holders can work down to the 16mm, but the X-PRO holder takes filters of 130mm width. Here I have a few questions:



1. Do I really need the huge X-PRO filters and holder for my 16-35mm lens? Is there a smaller holder that work with the lens at the 16mm end?



2. What do you do when you use square GND filters with a super-wide angle lens? Is hand-holding is a common approach?



3. If I have to hand-hold the filter, is long-time exposure a problem? Will the movement of the filter affect the quality of the image? For hand-holding, is a 85-110mm filter too smaller?



Any comments and advices are welcome.



Best regards，

Frank