Soft GND8 Graduated Filter ND0.9(3 Stops) 100x150x2mm Square Filter HD Optical Glass Waterproof ND Filter,Nano-Xcel PRO Series

SKU: SKU.1810

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They fit all filter holders that don't have to have an additional seal glued to the filters. I use it myself with the Rollei Mark II filter holder and the Haida M10. 
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At least in the pictures I don't notice any disturbing reflections. Always remember that lenses can also produce something without a filter, especially with backlight, for example when the sun is low in the sky. 
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There are coatings on both sides, and the middle is transparent.