The dichroic mirror is a mirror with significantly different reflection or transmission properties at two different wavelengths, it’s characterized by almost complete transmission of light at certain wavelengths and almost complete reflection of light at other wavelengths. It can be widely used in Laser technology applications.
A Neutral Density filter allows a photographer to control the exposure in an image very easily. The filter stops light reaching the camera sensor, therefore allowing us to leave the camera with a higher aperture for a longer amount of time.