A UV filter minimizes the blur that can be created by UV rays. It also shields the lens from dusts and dirts. The UV filter although a good accessory comes with some crticism. In the post we would shed light on the good and bad of the filter.
Types Of UV Filter
There are four different types of UV filter which are:
– Ordinary UV filters
– UV filters with multicoating (Anti-reflective treated)
– UV filters in the model slim (Designed to avoid vignetting)
– UV-IR-CUT ( Designed for camcorders (CCD & CMOS)
Benefits Of UV Filter
1. The UV filter serves as a shield to the camera lens
This is one of the greatest benefits of the UV filter. Important to note however, is that the filter protects the outer glass element of the lens from dust, stains, and scratches that could affect the lens, but does not protect against damage caused by careless handling of the lens, for example if the lens accidentally falls to the ground.
The filter is circular and can be easily unscrewed from the lens, which makes it much easier to clean. In the event that the UV filter becomes degraded than the lens, it costs significantly less to buy a new filter than to buy a lens, or repair a broken less.
2. The UV filter minimizes ultraviolet light. Old film cameras, and CMOS camcorders are extremely sensitive to UV light.The filter reduces the UV light, therefore providing better sharpness of the image. Although this doesnt really apply to modern digital camera, as most sensors in modern digital cameras are quite insensitive to UV light, so the problem of image sharpness being destroyed by UV light no longer applies to some extent.
3. A dirty lens alters the image quality. Dirt in all its forms destroys the image quality of your images. Whether it is unwanted grease stains or some other forms of lubrication.This can be avoided with the use of a UV filter. It is easier to wipe off dirt from a UV filter than to do the same on a lens. Even the smallest amounts of dirt and dust would give a noticeable deterioration of the image quality; unless you are shooting under a strong light source that casts its light on all the small dust grains of optics.
Tip: If the UV filter is difficult to remove, you can use a filter opener that makes it easier to unscrew the filter.
Disadvantages Of UV Filter
1. The UV filter is an extra glass element that causes more reflections which in turn gives a more blurred image. The number of reflections between the glasses increases, and in turn increases the lens flare.
A Lens flare is when reflections are created in the camera optics which then give ugly light bodies and a degraded color contrast in the image you take.
The glass surfaces of all camera lens as well as the glass surfaces of different camera filters increase reflections in the camera optics. Modern lenses consist of up to 15 or even more glass elements, and any extra glass element in the form of a camera filter does not ideally give a noticeable increase in reflections in most situations but can give an increased lens flare in bright backlight.
A possible solution to reduce reflections is to buy UV filters with multi-coating, although these type of filters are a bit more expensive than the ordinary types. Multi-coating filters are anti-reflective, thereby minimize reflections which in turn preserves image sharpness:
2. The UV filter reduces the light transmission to the camera to some little extent. High quality filters usually don’t have these problem.
3. The UV filter causes vignetting
Vignetting is when any part of the camera optics is included in the image. In this case: The UV filter is included in the picture.
Vignetting usually occurs with UV filter when you are shooting with a wide angle lens
A possible solution to avoid vignetting is to buy a slim model UV filter. Camera filters of the slim model have a thinner ring, therefore having a lower risk of causing vignetting.