Cokin filter overview

Graduated filters
Polariser filters
UV filters
Summary

Matt Grayson explains about three important filters in the Cokin Creative filter system.

Invented by Jean Coquin, a French photographer, the Cokin Creative Filter System has become one of the largest ranges of filter systems available today. They come in various sizes according to the skill level you feel you're at. The A system is for amateurs and consists of smaller filters to fit standard focal lengths. The P system is for professionals and the filters are larger to accommodate wider focal lengths or lenses with a larger front element. These two sizes are widely copied by independent companies so that the systems can be integrated with each other and I think it's a true testament to how popular the systems are. Two newer systems have been introduced from the original concepts called X-Pro and Z-Pro. They're even larger than the P series and are designed for use on medium and large format cameras.

The systems break down into separate parts which sounds annoying when you're buying them but is in fact a very intelligent way of doing things. Attached to the lens is a filter ring which then attaches to an filter holder which you then slide your filter into. The great thing about this is that it means you can simply buy a new filter ring for each lens that has a different filter size. With other filter systems, you have to buy a new filter and if you're looking at a circular polariser, it's a lot of money.

There are many filters available in the Cokin catalogue but we'll cover some of the most important ones you'll need if you're deciding to invest in the system.

Cokin Creative filter system: Graduated filters

The graduated filter is coloured at one end and fades to clear.

Graduated filters are easy to spot because half of them are clear while the other half will gradually fade to a colour. They're particularly useful for landscape photography because it means you can tone the sky a different colour, or enhance the blue, without affecting the land. It means less work in Photoshop but there's a margin of error with the colour bleeding over onto the ground if the filter is misaligned. Also if your lens doesn't have internal focusing, as the lens twists round to get focusing, it will also rotate the filter and send the alignment out. There are lots of colours to choose from and each will have a different benefit. I enjoy using a light tobacco graduated filter because it warms up the sky when the sky is trying to give a good sunset but can't quite make it. Something I find happens a lot in the Peak District where I shoot a lot of my landscapes.

Cokin P graduated filters range in price from around £16 to £19 and are available from Warehouse Express here:

Cokin P graduated filters

Cokin Creative filter system: Polariser filters
Polarisers are an important part of photography because they're possibly the only filter that can't be replicated in post-software. They work by cancelling out or allowing polarised light - depending on where the filter is positioned - and if you allow the polarised light to come through, a camera won't record the non-polarised version so the information is generally lost. With a polariser, you can cancel some reflections from water and windows, deepen blue skies and increase saturation on bold colours such as green or red.

Circular polariser filters cut polarised light allowing you to remove reflections on glass and water.

Because they perform more than one task it makes them good value for money although they generally cost more. There are two types to look out for: linear polarisers and circular polarisers. Linear polarisers are only effective when used on a manual focus lens and this is because the beam splitters that an autofocus DSLR uses for focusing a metering depend on polarisation. Using a circular polariser obviates the issue and the two filter types work in the same way. Cokin polarisers are like any other polariser in that they're round unlike the square filters in the rest of the Cokin catalogue.  However, they still don't have the screw thread. The round shape is simply to aid rotation of the filter to speed up the process. Each filter has several slots to add more than one filter and right at the back is a slightly wider one with a lip at the bottom. This is the one that the polariser fits into and sits on the lip to prevent it falling out. The filters are generally ridged around the edge to allow a good purchase when rotating.

The Cokin P Circular polariser costs £69.99 and is available from Warehouse Express here:

Cokin P Circular polariser

Cokin Creative filter system: UV filters

UV filters do little to adjust the image unless using a strong type. Mainly they're there to protect the lens.

UV filters are an important filter to have while also being pretty unimportant. They're important because they play an integral part of the process by sitting over the glass of the lens and simply protecting it from bashes and scrapes. If it gets smashed, the precious lens is protected and you can simply buy a new one which is much cheaper. They're unimportant because they don't alter the quality of the image or affect the exposure unlike the polarisers and graduated filters which can alter it by a few stops in some cases. In circumstances where there's a high amount of ultra violet rays, a strong UV filter will help by cutting out the UV haze and also cutting down on purple fringing.

There are some possible downsides to using a UV filter such as a loss in quality even though the filter is clear. The quality of the filter will determine how well it performs and remains in the background. The Cokin UV filters aren't screwed into the lens filter thread in the same way other manufacturers do, so you won't get the worry of the lens hood not fitting correctly or possibly vignetting the image if you have a wide lens.

The Cokin P UV filter costs £11.99 from Warehouse Express here:

Cokin P UV filter

Cokin Creative filter system: Summary
The Cokin Creative Filter system is so adaptable to your shooting style, you should be able to get better results almost immediately. The three part system is set up to ensure you get as much value for money as possible

The great thing about using filters is that it takes all the ground work back to the front-line where it was all those years ago in the days of film.

It means you have to think more about your photographs, slow down and take your time to work out what you want to achieve. My advice is to invest in the system, get out and take some photographs. Enjoy seeing what different effects you can create by using the filters in different situations and by merging them together.

For more information, go to the Cokin website here:

Cokin Creative filter system