UV filters actually working?

[Compaq]

Conclusion: UV filters serve no purpose image quality wise, and is a waste of money, though it might save your front element, one day.

Is this true?

 

[480sparky]

There's two schools of thought.

1. UV (or skylight) filters degrade IQ, so they shouldn't be used.
2. UV (or skylight) filters might protect your front element against damage that can affect IQ.

Those who subscribe to one school are never going to convince the others they're wrong.

 

[Compaq]

But how do they relate to their actual name: UV filter.

 

[Big Mike]

HAZE & UV FILTERS

Nowadays UV filters are primarily used to protect the front element of a camera lens since they are clear and do not noticably affect the image. With film cameras, UV filters reduce haze and improve contrast by minimizing the amount of ultraviolet (UV) light that reaches the film. The problem with UV light is that it is not visible to the human eye, but is often uniformly distributed on a hazy day; UV therefore adversely affects the camera's exposure by reducing contrast. Fortunately, digital camera sensors are nowhere near as sensitive to UV light as film, therefore UV filtration is no longer necessary.
photo of a 77 mm UV filter on a lens

However, UV filters have the potential to decrease image quality by increasing lens flare, adding a slight color tint or reducing contrast. Multicoated UV filters can dramatically reduce the chance of flare, and keeping your filter very clean minimizes any reduction in image quality (although even invisible micro abrasions will affect sharpness/contrast). High quality UV filters will not introduce any visible color cast.

For digital cameras, it is often debated whether the advantage of a UV filter (protection) outweighs the potential reduction in image quality. For very expensive SLR lenses, the increased protection is often the determining factor, since it is much easier to replace a filter than to replace or repair a lens. However, for less expensive SLR lenses or compact digital cameras protection is much less of a factor — the choice therefore becomes more a matter of personal preference.

Another consideration is that UV filters may increase the resale value of the lens by keeping the front lens element in mint condition. In that sense, a UV filter could also even be deemed to increase image quality (relative to an unfiltered lens) since it can be routinely replaced whenever it is perceived to adversely affect the image.

From Choosing a Camera Lens Filter

 

[Garbz]

Conclusion: UV filters serve no purpose image quality wise, and is a waste of money, though it might save your front element, one day.

Is this true?

Basically yes. Digital cameras aren't very sensitive to UV (they are hell sensitive to IR though which is why there's a hotmirror in front of the sensor). Also typical glass isn't very transmissive in the UV range either which also cuts down it's effect. In the past though film has had it quite bad with UV light, and a UV filter was quite effective in snow or sand where extreme UV is present.

I use them for protection and it's saved my arse plenty of times since I like taking photos and not coddling my camera. I haven't found any relevant quality issues unless shooting directly into a bright light source. ... On expensive filters anyway, the cheap ones are nasty.

 

[Forkie]

I can't be bothered with them. I use a lens hood to protect my lens.

 

[analog.universe]

There's two schools of thought.

1. UV (or skylight) filters degrade IQ, so they shouldn't be used.
2. UV (or skylight) filters might protect your front element against damage that can affect IQ.

Those who subscribe to one school are never going to convince the others they're wrong.

3. UV (or skylight) filters degrade image quality, and so should be removed in situations that make the degradation noticeable. The rest of the time they are easier to clean and cheaper to replace than a front element, and allow you to be a little more careless with your $2000 lens without putting it at risk.