How do photography filters work

Attaching a neutral density ND filter to your lens uniformly reduces the amount of light entering the lens. The ND filter is helpful when the contrast between the highlights and shadows is too great to get a quality exposure.

The Graduated ND is recommended for shooting landscapes and seascapes, because you can reduce the brightness of the sky for better contrast but still maintain an affecting exposure of the land or water.

Soft focus filters, do exactly that, they reduce the sharpness of an image, but only to an extent that is barely noticeable. With the help of a little diffusion; imperfect skin conditions are replaced by silky smooth skin. Remember you can use soft focus filters while photographing landscapes or monuments as well. Red filters are a favorite among landscape photographers and are often used to add drama. In nature photography, a red filter will increase the contrast between red flowers and green foliage.

A red filter will deepen a blue sky and make white clouds pop out. It can also decrease the effects of haze and fog. In some cases, depending on its strength, a red filter could even turn the sky black. Orange filters increase contrast between tones in textures such as tile or bricks, making it a good choice for general use and urban or abstract photography. It helps to darken the clouds slightly, and it also separates light green foliage from the darker shades of green.

Green filters lighten dark green foliage and boost light green foliage. They have a more specific use and are not as commonly used as the other filters, but green filters are extremely useful for the nature photographer.

Green filters may lighten the sky, so landscape photographers should take note of this when using it. Blue filters are not as commonly used in black and white photography because they lighten the sky and darken highlights or colors that are seen as light. While UV or Skylight filters can be employed to do the job, you can buy dedicated protect filters. They are completely clear and designed to be kept permanently attached to the lens — although you might want to remove them when using other filter types or a holder.

Protect filters do exactly that, guarding the front element of the lens against dust, dirt, sand, moisture and scratches. Manfrotto Professional Protect filters are designed with the professional and enthusiast in mind, who require maximum protection. The filter is water repellent and constructed to repel scratches and oil while boasting an antistatic and anti-reflective coating.

Overall, a protect filter is a very wise investment , potentially saving you huge sums should you drop your lens — after all, it is much cheaper to replace a damaged filter than it is a lens. When shooting landscape photographs in challenging weather conditions — when spray, snow, dust or sand are being blown toward the camera — I would recommend you keep a UV or Protect filter attached to your lens to ensure it stays clean and damage free.

For landscape photography, a polarizer is a must have filter. Arguably, no other in-camera filter will have a greater impact on your images. By blocking polarized light from entering the lens, a polarizing filter is able to restore natural saturation, contrast and vibrancy.

Doing so will result in photographs with added punch and oomph. Polarizers are typically circular, screw-in type filters. They are made from a thin foil of polarizing material sandwiched between two circular pieces of glass. They are intuitive to use. You should be able to see reflections come and go and the intensity of colours strengthen and fade.

The sun contains most polarized light in the areas that are at 90degrees to it. Metallic objects, like polished steel and chrome plate, do not reflect polarised light and so remain unaffected by the filter.

Using the filter is very easy ; simply rotate it until you achieve the effect you like. For landscape photography, a polarizer is most popular for making blue skies appear more vibrant. However, it is also useful for reducing the glare reflecting from wet and shiny leaves and foliage , making it a very useful filter for photography of woodland interiors, rural views and even close-ups of flowers. Manfrotto famous for its quick release filter adapters is among the brands producing high quality polarizing filters , available in a variety of lens diameters up to 82mm in size.

Arguably, a polarizer is the most useful and essential landscape filter. It is a filter with the potential to transform your images.

Although they are best known for their effect on clear blue skies, polarizers are great filters when shooting water and woodland interiors. They will eliminate the glare from water and radiating from wet, shiny leaves in order to produce results with far more colour saturation and impact.

Polarizing filters are renowned for their effect on blue skies. When I shot these colourful beach huts, I adopted a low angle and rotated my polarizer until the sky looked at its most saturated in order to achieve maximum impact.

The full effect of a polarizing filter can look very seductive through the viewfinder. However, the most pronounced effect will not always produce the best, or most natural looking result.

Be mindful of this when using one. When fully polarized, you can encounter certain problems, for example over polarization. This will create unnatural looking results, so be careful not to overdo the effect. Cloudless skies and photographs taken at higher altitudes are at most risk of looking too dark. You should be able to detect the problem through the viewfinder, but always review your images and check that skies remain natural looking. If skies look too dark, simply reduce the level of polarization by rotating the filter.

Uneven polarization is another common problem. At certain angles to the sun, you may find the effect of the filter is irregular — with the sky being darker in some areas, more than others. Short focal lengths, between mm, are most prone to the problem due to the broad expanse of sky they are able to capture. When pushed to the extreme in bright light , when the ND filter needs to be exceptionally dark, the resulting image can sometimes become uneven. Occasionally the camera also assumes you're trying to take a dark image and you may have to adjust your exposure compensation a little until you get the settings you're after.

Alternatively you could play around in manual M mode with test shots until you reach an exposure you're happy with. Because everything looks so dark through exceptionally strong ND filters, you may find that a it becomes impossible for your camera to auto-focus AF through it, and b impossible for you to see your composition.

In these cases, it's best to frame up your composition and pre-focus using AF before you put on the ND filter. As you'd be using a tripod anyway with such slow photos, neither the focus nor composition will change. To prevent the lens hunting for focus once the filter is applied, after you've pre-focused with AF it's best to switch your lens to manual focus MF. This will 'lock' your focus. Alternatively, some lenses also have a focus distance scale physically displayed on the lens, allowing you twist the focus ring to approximately the right focus distance.

Quick tip: Look for creative compositions that are created by movement eg. Correct exposure across most of the bottom image, rather than a correct sky and darker rock [top image].

They are always square or rectangular and therefore require a 'system' mount or awkwardly hand-held in front of the lens. In today's world of digital post processing, ND grads are far less common, but shouldn't be entirely overlooked. System filter with ND Grad When watching a beautiful sunset through your own eyes, despite the light and colours being extreme, as you look around you'll find it easy to see into both the bright sky and the darker shadows equally well.

Our minds are very intelligent and balance the bright areas and the shadows for us subconsciously. However for a camera, it's impossible to capture both the bright sky and dark foreground evenly.

All cameras, of every make, continue to struggle when confronted with high-contrast conditions or scenes where the brightness range varies dramatically across the image. Unless something is used to reduce the brightness of the sky down to a similar level to that of the rest of the scene, the photographer is faced with the option of 'correctly' exposing the shadows which results in bleaching the sky or 'correctly' exposing the sky blackening the shadows and creating silhouettes.

ND Grads help to overcome this issue by their ND gradient, allowing the photographer to darken the brighter areas of the photograph sky through the filter while keeping the darker shadows unchanged, giving 'correct' exposure across the entire image. Graduated Filter in post processing, bringing out the definition in the mountain. Quick tip: Adobe Lightroom and Adobe Photoshop RAW provide a convenient graduated filter you can apply in post-production with a simple click and drag.

It won't completely solve your problems, and post processing is always going to affect your image quality to some degree, but it's a very helpful tool nonetheless! You can also digitally apply other graduated effects too - not only ND. For example you could opt to make the sky more saturated or bluer. The creative options are numerous.

Tips for all filters: Be selective in your filter use. While a UV should be a near permanent fixture, don't always just assume using a creative filter will make for a better photo.

A filter won't necessarily bail you out from a taking a bad photo, but it will help you take GREAT photos. Be keen to maintain image quality. Don't stack filters on top of each other unless you have to. The more pieces of glass that the light has to pass through, the lower the image quality will be. Be wary of 'tunnelling' or vignetting when using wide angle lenses. Be on the lookout for quality. You get what you pay for.