The Kase K9 holder system has an innovative solution to the problem of using circular polarizers with slot-in systems. Rather than being mounted as the last filter, making it large and allowing the possibility of light being reflected back into the lens. The Kase solution is to mount the polarizer at the back of the system, allowing you to have up to three Neutral Density or Graduated Filters in front of the polarizer.
The polarizer is mounted to a geared lens adapter ring, that is then turned simply by using a gear on the holder when attached to your camera. To mount the polarizer, it’s simply a case of placing it into the geared ring magnetically, removing the hassle of trying to screw a polarizer into place. The K9 holder is compatible with modern lenses up to 14mm on a full frame system* without vignetting.
The Kase holder is precision CNC milled from the highest quality aviation grade aluminum with a mat anodized finish to reduce reflections. Both strong and lightweight, the holder uses a screw locking mechanism to prevent accidental removal.