A skylight camera filter is one of the best investments you can make for your camera lenses. This camera filter is made to filter out the UV rays from your photographs while letting normal light in. Why should you care about UV rays? UV rays are light rays in the non-visible spectrum and natural sunlight is abundant in UV light which is why you have to put on sunscreen on sunny days. Though they are not visible, UV rays make photos look like they have a blue haze and distort some picture slightly. So a skylight filter can greatly improve the clarity of pictures that are taken at high altitudes or of distant horizons which can be affected by UV light. Some may be confused by the difference between a skylight filter and a UV filter. A skylight filter differs slightly from a UV filter in that the skylight filter has a slight pink color cast which also warms a picture. It tends to attenuate the blueness of scenes while the UV filter just cuts down on the blue haze. Whether to use a skylight filter or a UV filter depends on a photographer's preference.

The differences between a UV filtered image on the left and a non-filtered image is shown on the right. The filtered image shows slightly less distortion in the clouds and more green in the ocean.

A skylight filter also has the advantage of being very cheap. A typical one can be purchased for less than 1/10th of a camera lens. So many photographers add a skylight filter to their lenses to not only filter light but also to protect the lens. The filter protects the lens from dirt, fingerprints and collisions as well as a lens cap. The advantage is that the filter does not have to be removed before taking a picture. These filters come in all shapes and sizes to fit any lens. Indeed, some photographers keep a skylight filter permanently affixed to each of their lenses.

skylight filter image

Additional facts about skylight filters

  • Most digital camera CCD sensors filter out UV light. So a skylight filter only provides the pink warming which tends to reduce the blueness of pictures as well as provides lens protection. Some photographers consider the lens protection to be the main benefit of a skylight filter.
  • Filters have mounts are made from plastic, aluminum and brass. Both aluminum and plastic mounts can easily cross thread and may bind. Brass mounts on the other hand do not cross thread and are less likely to bind.
  • The thread size of the lens has to match the thread size of the filter. The thread size can be found on the lens barrel at either at the front (between the glass and threads) or at the bottom. This number is always preceded by the "ø" ligature symbol.