Tunable filters are optical filters that are suitable for applications requiring wavelength tuning. Two of their main specifications are the optical density (OD) and the out-of-band rejection. The ...

A quality ND filter (short for neutral density filter) cuts the amount of light coming into the camera without affecting the color or overall appearance of the image. While photographers often want ...

If you are ever planning to shoot photography outside — whether it be a vibrant cityscape or gorgeous landscape — you will want to use a neutral density filter (or ND filter). An ND filter essentially ...

Fig 1. Density addition and subtraction can easily separate these audio channels before digitalization. Fig 2. Density multiplication can easily be used to multiply these two inputs in several ...