Essential Camera Filters Guide
There are many filters that are useful for different situations and types of photography, but there are two filters that are a must have for every serious photographer, and they are the ND grad and polariser filters. But do we really need to use filters now that we can recreate their effects in-camera, using Photoshop and even on smartphones?
As a rough guide, there are two types of filters- coloured filters and light adjusting filters. Coloured filters can be easily replicated in software such as Photoshop, whereas light adjusting filters such as the polariser it’s not so easy to. Two types of coloured filters are colour cast filters, such as warming and cooling filters and black and white coloured filters. Examples of light modifying filters are the polariser, UV and ND filters. Filters come in different types, the cheapest of which are resin filters, and the more expensive, higher quality glass filters. Coated filters are much higher quality than uncoated, and give additional benefits such as reducing flare, scratches and water repellent properties. If you’re looking to buy a filter, Cokin and Lee filters are probably the two most popular and best brands you should take a look at.
- Circular filters are the most common type of filter, and can be mounted straight onto the lens. Some examples of filters that come in circular form are polarisers, UV, ND and colour filters.
- Slot in filters are most often used for landscape photography, and can be stacked on top of each other. They are slotted into a filter holder that is attached to the lens by an adaptor ring.
ND Grad filters are almost always used to darken the sky in landscape photos, because the sky is often much lighter than the rest of the image, and so will usually overexpose or the rest of the image underexpose to compensate. Overexposing the sky can result in lost details and contrast, and so to remedy this an ND Grad is used to darken the sky and so balance the brightness between sky and land and expose the whole photo correctly. Graduated filters are half clear and half tinted to reduce the amount of light entering, and they come in strengths according to their light blocking ability, for example x2, x4 and x8 which translates to one, two and three stops of light blockage.
As opposed to ND grad filters, neutral density filters reduce the amount of light for the whole of the image and so are useful for different situations. If you need a long exposure and using a smaller aperture and ISO isn’t an option, an ND filter will enable you to do this, even in daylight. They are often used to add blur or create a smooth water effect, which is done taking a long exposure of a waterfall or river.
Polarisers are probably the most useful filter which everyone should have one of. They are often used to increase saturation, and especially useful for creating dark blue skies. Polarisers can also reduce reflections in water or glass etc. by reducing the amount of reflected light going through the filter. They can also be used as a neutral density filter to reduce the amount of light entering the lens, which equates to about two to three F stops of light. For the best effects the camera needs to be pointing in a direction about 90 degrees from the sun, but if you point the camera directly towards the sun you might not notice any effects at all. You can then rotate the filter and you will notice reflections and saturation changing as you rotate.
Ultraviolet light can’t be seen by the naked eye, but some of the effects of it can. When UV light interacts with air, it creates a haze that you often see in landscapes in the distance. A UV filter can help reduce this haze, and as a result increase the contrast. A lot of good lenses filter UV to a degree, but it is also worth investing in a UV filter. A lot of photographers use UV filters as a lens protector, which is kept on all the time to reduce dust and scratches from reaching the lens, and can be replaced a lot cheaper than a lens. The negatives of UV filters are cheap ones can reduce the image quality and contrast and increase the chances of flares.
These are clear filters that are designed to protect your lens from dirt, scratches and bumps. They don’t modify the light entering through them, but buying a quality one is essential if you want the best image quality possible.
White Balance Filters
Cooling and warming filters are used to change the white balance of your photo, and correct any colour casts. They are not used as much now as they were in the film camera era, due to advanced in-camera white balance settings and post processing which can correct this problem easily. But in some rare situations where the camera isn’t able to fully correct the white balance, a filter could come in handy.
Black And White Filters
The problem with black and white photography is when converting contrasting colours to black and white, they often don’t retain the same contrast and turn out differently to what you expected. Filters for black and white photography come in a range of colours, most commonly red, orange, yellow, green and blue. They work by reducing the amount of light from all the other colours except the filter colour, and have the effect of increasing the brightness of the corresponding filter colour in the scene. For example using a green filter would increase the brightness of all the green things in the scene, such as foliage and make it appear a lighter grey or white, while decreasing the brightness of all the other colours making them appear as dark greys to blacks. Red filters are known for creating the most dramatic effect, and in landscape photos will turn a blue sky and clouds very dark and contrasty. However yellow filters have the weakest effect of all the filters, and are useful for slightly increasing contrast in the sky and are good for foliage. The orange filter is probably the most commonly used, and strikes a good balance between the red and yellow filters, and is useful for portraits, urban and landscape photos.
Close-up filters magnify your subject much like a magnifying glass, and allow you to take shots closer to your subject, which is useful for macro photography. The focus distance capabilities of your camera then moves a lot closer, so if you try using one of these filters for anything further away, it might not be possible to focus.
Soft focus filters reduce the sharpness in your image, and are especially useful for portrait photos to reduce the appearance of blemishes and give the skin a soft and smooth look.