CP Filter

Three reasons to use a CP Filter by Adam Jacobs

I often get asked why photographers / videographers should use CP (Circular Polarizer) filters. Here’s a few reasons why they are a must, especially for landscape photographers:

Before Through CP After

Using a CP Filter:

  • Increases saturation

  • Boosts Contrast

  • Improves Clarity

You can see the dramatic effect of using a CP in the photo examples on the right..

Here’s how they work:

A Circular Polarizer (CP) filter blocks certain light waves reaching the lens which have been directly reflected towards the camera at specific angles. Unlike other filters, a CP involves a certain amount of adjustability and has a rotating ring that you can manually control. This ring, when rotated, blocks specific light waves from entering the lens and subsequently reaching the camera’s sensor.

Given that the angle of light being filtered is important, so is your position to the sun to determine how light will be filtered and the resultant effect on the image. The strength of the effect of the filter (amount of polarization) varies greatly depending on the position of the sun, time of day and season. For example, you can change the angle that is filtered by moving your position in relation to the sun. The strongest polarizing effect is always achieved when you are perpendicular, (90 degrees), to the way that the sun is facing.

Unlike a UV filter, a Circular Polarizer is not totally clear . Instead, it is translucent with a grey-like tone appearance. It blocks certain types of light that are reflected towards your camera at certain angles from reaching the camera’s sensor. By filtering out a specific type of light, a CP filter affects the brightness of the exposure and always darken the overall photograph. This is usually by a reduction of two to three f stops of light. Therefore, certain camera adjustments need to be made to compensate for this loss of light to ensure that your photograph will not be under-exposed. I usually just push up my ISO to offset the slight loss of light once the filter is snapped on or slow down my shutter speed when on a tripod. 

BEFORE

WITH CP - CHECK OUT THE DIFFERENCE IN THE SKY AND WATER

Adam Jacobs | Manfrotto Filter Videos and E-Book by Adam Jacobs

I've spent a lot of the past year working on a project with Manfrotto to create educational material to coincide with the launch of their new filter products and Xume system. This materials are focused on helping one better understand how to use filters to improve your photography. This has culminated in the launch of a landing page on Manfrotto.com containing videos, an e-book and shorter pamphlets. These are all designed to teach you how to better understand how using different filters can help create better images.

In both the videos and book, I cover the three main filter types (UV, Circular Polarizers and Neutral Density) and explore what each one does, their advantages and in what situations each comes in useful. Below are the three videos.

Also, click here to download the entire e-book for free. Enjoy! 


Click on the image above to view the landing page that I have created with Manfrotto which has a bunch of great material on learning to better use lens filters to improve your photography. 

Click on the image above to view the landing page that I have created with Manfrotto which has a bunch of great material on learning to better use lens filters to improve your photography.