How Camera Filters are Made
When it comes to making camera filters like ND filters, we may think that the process of manufacturing them is pretty straightforward. But to make excellent filters like the Lee filters, a lot of technical knowledge and quality control are needed.
Just check out this pretty fascinating video that goes inside Lee Filter’s factory to see how the filters are made. Some of the work are done by machine, but some, like dyeing the graduated filters, are done by hand.