As I now have two lenses – yes, two! – I wanted to invest in another UV filter for protection if nothing else. I had also been told that a Circular Polarising Filter was very useful for having more control regarding skies and water, and after looking at a few articles to find out more (including this one on Wikipedia) I duly investigated and bought a set of 4 filters that came in a case – the UV and CPF came with a Fluorescent filter and a warming filter. The CPF itself has an adjustable ring, meaning you can turn the front part to get different effects.
The two images below were taken with the CPF at different points in its rotation. I’m not sure how to describe where in its rotation the filter is, but as I’m looking through the lens I can see the effects before choosing to take the picture.
In this first image the sky is fairly flat behind the larger clouds, and the sea is a fairly deep blue. The rocks are also fairly dark.
The second image below was taken with the same settings, the only difference being the rotation of the filter.
In this image, the higher clouds are much more defined, and the sea is more of a grey-blue. There is also noticeably more detail in the brighter rocks, and there is less contrast between the sea and the sky. I’m sure I will get a lot of use out of this filter, especially in snowy conditions when the brightness of the snow could overwhelm other details.
Other uses of this filter include removing unwanted reflections from windows and water. With the polariser it is possible to look through shallower water rather than seeing a reflection of the sky. I’m very happy with the versatility provided by this filter, especially as I wouldn’t be able to replicate this using editing software.