Hi,

I've designed a welding glass filter holder for a Leica-Lens 14-24mm. The welding glass can be used as a makeshift ND-filter. 

Thanks to https://www.thingiverse.com/sdraxler/designs for the inspiration.

I've designed everything with Microsoft 3D… but I'm working on my Fusion 360 skills ;-)

The design and the make can certainly be improved

The filter holder can be adapted to any diameter, by simply changing the diameter of the outer ring.

I've put sticky felt on the brim of the holder (take the IKEA felt that comes with the KALLAX) to ensure light insulation. The tape on the backside is for light insulation as well, since I didn't want a tight fit, not to scratch the frame of the lens. The inserts on the base of the holder are M3 melt inserts.

The pictures are interestingly green, but can be modified by playing with the white balance in a editing software…

The welding glasses come in different shades - the higher the DIN Nr the darker they are

DIN 9, DIN 11, DIN 13

Have fun with these inexpensive ND-filters (~10€ for 10 pieces in online stores)