Ultraviolet light is well known for its harmful effects. It happens that it can interfere negatively with camera film. It is electromagnetic radiation primarily from the sun. Ultraviolet light has a wavelength that is 10nm to 400nm. This is shorter than the standard visible light wavelength. It is usually present when shooting in bright conditions and results in a blue haze on the image.
The bluish haze used to be a significant problem for those using traditional film. Yet, modern digital sensors have proven insensitive to UV even when shooting in bright light. The solution to the problem was the use of UV filters. A UV filter blocks the UV radiation from entering into the camera with the rest of the light.
Even with the modern digital sensors that do not have the atmospheric haze when shooting. The use of UV filters still gains popularity for other purposes. One of the biggest is protection to the lenses. It is this use that has created a huge UV filter vs no filter debate. The debate is to determine whether the filters are a worthy investment. Making them an essential camera accessory.
Does a UV filter affect image quality?
Perhaps the biggest argument against the use of a UV filter is the claim that they affect the image quality. Especially on aspects like image sharpness, resolution, clarity and even exposure. The claim is based on the premise that more glass elements added the more opportunity for refraction of light. Thus, there are high chances of creating a ghosting effect, loss of light and also flaring. Most of the tests reveal that the impact on the image quality is on the image sharpness. Not on resolution or exposure.
The occasions where the effect occurs are rare. One is shooting towards a bright light with a dark background and mostly when the aperture is wide open. As light comes into the camera, it has more surface to bounce off. This ends up creating a ghosting or flare effect by creating a spot of light on the image where there is not light. The ghosting and flaring up is the one aspect that the UV filter has been shown to impact on the quality of the image.
Yet, most of the photos taken in tests with the UV filter both on and off, show a lack of any impact on resolution and exposure. In some few instances, it has been noticed that the image clarity for objects in the far distant may be affected. In such cases it is minimal, and it can be easily fixed with the use of Photoshop. To avoid such an instance, when shooting in the conditions described above. Remove the filter and use it later on.
Benefits of using UV filters
If your camera is equipped with digital sensors, then you may be wondering why the sellers and manufacturers will be urging you to get a UV filter. And if you will even use it at all. Yet, the UV filters offer several advantages including the following;
1. Cut out UV light and remove the blue cast effect
The primary job of UV filters is to prevent light from getting into the camera by absorbing 90% of the UV light. They are available in three main categories of rating; L37, L39 and L41. An L37 filter absorbs UV light below 370nm, and L39 absorbs UV below 390nm, and an L41 absorbs 90 % of UV light below 410nm. By removing the blue cast effect caused by the ultraviolet light. The UV filter allows you to meet a better and realistic white balance of the scenes you are shooting.
2. Cut chromatic aberrations in certain lenses
In simple terms, chromatic aberrations refer to the appearance of color shades where they are not supposed to be. You can use UV with certain lenses to correct the chromatic aberrations.
3. Offers protection to the lenses
For most people, UV filters main purpose is to protect the camera. This is by having an extra layer of glass before the camera lens. You can protect your camera from risks such as scratching and drops. Also protect it against rain and dust especially if it is the kind of lens which has the front element moving when you zoom. Replacing a UV filter will cost you under 100 dollars while replacing a lens can go to several thousand.
On the drops aspect, it mostly depends on the quality of glass used to make the UV filter. While the standard optical glass strength will help in reducing the impact. It is only the heavy duty filters made from hardened optical glass that is four times stronger than the standard one. This will offer reliable protection to your lens from knocks and drops.
4. Easy cleaning
Whether it is fingerprint smudges, specks of sand and dust, as well as the occasional grime that may be accumulating. Then cleaning the UV filter is much more comfortable and safer than working on the lens. Some people also find them more reliable than using hoods if you practice shooting on the go.
Cons of using a UV filter
Besides the potential of interfering with the image quality already discussed. The downside of having a UV filter is the extra cost they bring as well as the extra weight. At times they are also the ones that trap dust necessitating frequent cleaning.
Cheap vs expensive filters
How much a filter helps or impedes your photography, is determined mainly by its quality. Higher quality filters can filter UV light across a wide range. They also come with sturdier glass making them better for protective purposes. For this reason, they are expensive. So, cheaper UV filters increase the risk of affecting image quality. They are also light and do not offer any meaningful protection to your lens in case of drops and knocks.
If you have not made up your mind by now on whether to use a UV filter or not. Then you can follow the simple principle everyone in the UV filter vs no filter camps agrees on. If you have to use one invest in a quality one even if it may cost extra.