It’s a loaded question, to be sure, so let’s unpack it.
Filters are made from a variety of raw materials including glass, plastic, resin, polyester, polycarbonate, quartz, or a composite of these materials, and how well a filter is constructed will determine how effective it is in the field. In short, a good filter is one made with quality materials that is well crafted.
Aside from materials and craftsmanship, the “best” camera filter depends on what you’re using it for. There are many different types of filters that affect how your camera “sees” light, the most common types being ultraviolet (UV), neutral density (ND), graduated neutral density (GND) and circular polarizing (CP) filters. There’s also a slew of specialty filters available on the market to choose from depending on your needs, from macro lenses, thermal and infrared cutoff filters, to underwater color correction filters.
First, decide what type of filter you need based on your shooting style. Investing in a filter can be expensive, so think about how much you’re going to use the filter and how valuable the content is to you that you’re going to be capturing.
Resin, Composite and Polycarbonate filters
The most common type of inexpensive filters are resin filters, composite filters, and polycarbonate filters. These filters are typically fine to use on low resolution cameras, providing some image enhancements over the stock lens. However, when using this type of filter on a high resolution camera like the newest Sony Alpha 7 or production heavyweights like the RED Weapon 8K, you’re going to get more noise.
Resin, composite and polycarbonate filters are best used on lower resolution cameras, giving less sharp results when used on high-res platforms. Of these “budget” filters, polycarbonate will give the best results. Suitable applications include actions sports and underwater photography and videography, as this type of filter is more durable than glass or polyester filters and are less prone to cracking and scratching in extreme environments.
Glass filters offer sharper optical clarity than resin, composite or polycarbonate filters when used at high resolutions and on cameras with full sized sensors. Optically, there are fewer artifacts found in glass lenses than polycarbonate, composite or resin lenses, resulting in a more pure and neutral image profile. With glass, you’re going to get what you pay for, so if you’ve invested in a nice camera kit, it makes sense to get a quality filter. Thin glass filters are often more expensive, but tend to be optically clearer than thick glass filters, with the exception of macro lenses where the lens thickness is related to its magnification power.
In long exposure landscape photography, a quality glass filter will better hold your lens’ resolving power than a resin or composite filter. Conversely, composite filters made of polycarbonate or other hard plastics will hold up better in harsh conditions where the filter could be cracked or scratched, with the downside of added noise at higher resolutions.
Polyester filters are super thin and usually require a square or rectangular mount to attach over the front of a camera lens. Because they are so thin, polyester filters provide hard defined edges and are popular in portrait and studio photography. Polyester filters can be a cheap alternative to glass or composite filters, but because of their thinness should only be used in controlled settings.
Optically Polished, Pure Fused Quartz filters
Pure fused quartz filters are carved from single blocks of solid quartz resulting in filters that are optically pure and free from artifacts like air bubbles that can be found in cheaper resin, composite, polycarbonate and even expensive glass filters. Pure fused quartz filters like PolarPro’s Quartzline produce a refractive index much lower than any of the previous filters mentioned, with unparalleled UV transparency. In addition, these filters have a higher operating temperature range, being naturally resistant to thermal shock, moisture and freezing temperatures, making fused quartz more durable than glass or polyester but just as optically sharp.
It’s important to decide how you want your filter to attach to your camera. Square or rectangular filters can be used with matte boxes and drop-in filter mounts, while circular filters are typically threaded to attach to the front of a camera lens. If you are looking into circular threaded filters, choose brass over aluminum if possible. Brass is more durable, while aluminum filter frames can bind to the front of a lens and cause stripping to the front element.
-Resin and thick glass and plastic filters should mostly be avoided as their imperfections will only damage your camera lens’ resolving power (A thick macro lens is an exception).
-Polycarbonate filters will hold up best in action cam or underwater scenes.
-Polyester filters provide hard defined edges and are popular in portrait and studio photography. Because of their thinness, they should only be used in controlled settings.
-Quartz filters are both durable and optically pure, providing the highest UV transmission and operating temperature range of any optical filter material, suitable for production applications where a neutral profile and zero color cast are critical.
-Choose brass filter frames over aluminum frames when buying circular filters. Brass frames won’t strip or bind to the threads on your camera lens after repeated use.
-Think about what type of shooting you’re going to do before choosing between the various filter options. The best camera filter is the one you know how to use!
-Remember to clean your camera filters and lenses before each use for the best image quality possible.