The filters offered by Clare Chemical and Lab Supply Mall have exactly the same optical properties as the DarkReader amber screen. Attaching a filter to a digital camera usually requires additional accessories. For example, with most cameras, a "lens adapter" is also required. The adaptor screws to the body of the camera, over the lens. A filter can then be screwed onto the other end of the adaptor. In some cases, the thread size of the tube is 'non-standard' and so it is also necessary to purchase a 'step-up ring'. The ring is threaded at both ends: one end attaches to the adaptor and the other end will accept a standard-size filter. Adaptor and rings can be purchased from the camera supplier or Lab Supply Mall.
