The filter is made of glass and special dyes. The blue filter can only let blue light pass through. Compared with ordinary glass, the molecular structure and refractive index of blue filter have changed, and the passage of some color light has changed. For example, when a white light passes through a blue filter, it emits a blue light, while the green light and red light are very few, and most of them are absorbed by the filter. The filter plays a very important role. It is widely used in photography.

√ Microscopic instruments
√ Optical metrological instrumentsLaser protective windows
√ Optical instruments of surveying and mapping
√ Machine vision devices
√ Optical detection instruments
√ The popular science optical
√ A digital opticalOptical test instruments
√ Fiber optic instruments
√ Laser Instruments
√ Electro-optic displays
√ Medical opticalInfrared thermography
√ Observation instrument measuring instrument andphotography