What is the maximum amount of light a polarizer can transmit?

A single perfect polarizer will block 50% of incident light. Add in Fresnel reflections and you are at 42% transmission. For example, our TECHSPEC® Linear Polarizing Laminated Film transmits 38% for a single pass; so only about 4% is being lost to absorption. This is typical for linear polarizers because they are absorptive polarizers. Reflective, or refractive, polarizers like Glan-Thompson will have slightly better transmission, but these are typically not larger than 1” in size thereby limited the applications in which they can be employed.