Polarizers – What They Do and What Are They Good For?

Posted on by Kyle Spencer

A polarizer is an optical filter usually used on cameras to block certain light waves while letting others through. In photography, it can darken skies, reduce reflections, and enhance colour saturation by filtering out unwanted light that causes glare. Light waves travel in different directions and using a polarizer sections off waves going in certain directions lessening reflections and making the shot slightly darker.

polarizer photo lens filter
Here we see how it darkens the blue of the skies.

Thin film linear polarizers use glass layers on which a special optical coating is applied. The interference in the glass causes them to act as beam-splitting polarizers. The layers for the film can either be a plate, which is inserted into the beam at a particular angle, or a wedge of glass that is put into a second wedge to form a cube with the film cutting diagonally across the center.

 

polarizer photo lens filter
Here we can see how it removes the reflection off of the water.
How to Use a Polarizer
• Screw it onto the lens.
• Look through the viewfinder or LCD.
• Rotate the front ring until reflections decrease or colours deepen.
You’ll see the results immediately as you turn it and get darker skies, less glare and clearer detail.

VIDEO OF POLARIZER IN ACTION: