The Importance of Coated Lens Filters

Probably the most common reason people today put UV or protective filters on their lenses is to protect them. Scratching or breaking a relatively inexpensive single piece of glass seems much more appealing than potentially damaging the front optic on an expensive lens, and rightly so. UV and protective filters are an “insurance policy” for camera lenses, protecting them from scratchs, knocks, or worse. At our store here in Seattle, we’ve seen customers come in countless times with expensive lenses that have a scratched, cracked or even shattered protecive filters, filters that saved them from oftentimes very costly repairs. So using UV or protective filters is DEFINITELY a good idea!

Not all filters are created equal however. Some photographers shy away from using filters on their lenses because they believe “placing a $30 piece of glass in front of a $1000 piece of glass is counterproductive,” and in most cases they’re right. Inexpensive UV or protective filters typically are a bare piece of glass placed in a threaded ring. These bare glass filters are typically in the range of $10 – $30, depending on size. While they provide some level of protection against damage, they are also susceptible to large amounts of glare which can actually decrease contrast, clarity, and overall image quality.

Fortunately many filter manufacturers are wising up to this problem and are now offering single coated and multi-coated filters. These filters provide a substantial decrease in glare while still maintaining good image quality and the same, and sometimes better, level of protection as bare glass filters. Typically, the number of coatings a lens filter has, the better it is at reducing glare and maintaining high image quality.

At our store, we oftentimes will demonstrate for a customer the difference between a non-coated lens filter and a coated lense filter with a side-by-side comparison. This comparison provides compelling evidence of the drastic differences between the filter types. The images below compare two filters, a non-coated bare glass filter and a multi-coated filter.

Scene taken using a non-coated filter.

Scene taken using a non-coated filter.

 

 

Scene taken using a multi-coated filter.

Scene taken using a multi-coated filter.

By comparing the two filters, one can see that the non-coated bare glass filter produces much more glare than the multi-coated filter, particularly in the lower right portion of the frame. This glare translates directly into lower contrast and reduced image quality. So next time you’re picking up a UV or protective filter to prevent any damage to your lens, make sure you get one with anti-glare coatings to ensure you’re getting the best pictures possible!

-CameraTechs Staff