April 08, 2013, 11:54 AM — You can energize a conversation with photographers in innumerable ways. You could, for example, try to build a case for Nikon over Canon, or perhaps argue that sensor size doesn't really matter. Or you could advocate using protective filters on all of your lenses.
I find the third topic intriguing, for both advanced shooters and newcomers alike. What filters, if any, do you need for your lens? Several appealing options in a range of prices are available.
Let's start with the different types of filters. I recommend three to consider: protection, polarizer, and neutral density. In the world of protection filters, those commonly used are clear, UV, Skylight, and Haze. Here's a quick overview.
UV--Typically, this filter is very pale yellow to virtually clear. In the past, UV filters helped protect your image from the negative effects of atmospheric ultraviolet radiation. But thanks to the improved high-tech coating on today's lenses, these filters don't have much impact on image quality at lower altitudes. Some effect may be noticeable at high altitudes, however. Their primary use today is to protect the lens itself.
Skylight--Light pinkish in color, this filter can help correct the slight blue cast from shooting outside under a blue sky. Some photographers see benefits for their landscape photography. I don't recommend this filter for portraits because it can affect skin tones.
Haze--This is essentially another name for a UV filter.
The above filters were very popular in film camera lenses. But with digital cameras, we can now counteract the mild effects of UV light with the white balance settings in our cameras. So, even though UV and skylight filters do have some mild filtering effect, they are primarily used as protection filters.
I recommend that you use a high-quality, multi-coating glass filter if you want protection for your lens. You don't really need UV or skylight under most outdoor lighting conditions.
Specific protection filters
I typed the term protection filter into the search box at B&H Photo. Among the hundreds of results listed, here are a few good examples:
Tiffen 52mm UV Protection Filter ($5.20) This filter helps absorb ultraviolet light, reduces the bluish cast of daylight, and serves as a general protective filter.
Hoya 58mm EVO Clear Protector Filter ($57) This offers a clear filter for protection, a low profile, and a rigid, aluminum filter ring. The coating prevents surface reflections.
Heliopan 72mm Protection Filter ($780) A clear filter for protection, the SH-PMC provides a 16-layer multi-coating, brass ring construction, and high-quality Schott glass.
That's quite a price spread among three filters of different sizes and different qualities. Generally, you don't have to use a UV or skylight filter if all you're after is protecting the lens. A clear filter is all you really need. Here are three things to consider when choosing this type of filter:
Multi-coated surface to help improve contrast and reduce reflections. For best results, the quality of the filter should be on a par with the quality of the glass in your lens.
Appropriate thickness for the type of lens you're mounting the filter on. On my 16-35mm wide-angle zoom, I have a filter with a thin mount so it doesn't cause vignetting when the lens is set to its widest field of view. For my long zoom lens, such as a 70-200mm, it doesn't make any difference how thick the filter mount is.
Brass or aluminum for the mount. The theory is that brass mounts tend to be easier to unmount from the lens than their aluminum counterparts. Some photographers believe that they don't "freeze up" as often, when they then require a filter wrench to remove. I don't have any conclusive data on the superiority of a brass mount, but I will say that I like the feel of brass better.
The two main benefits of a polarizing filter are to reduce or eliminate reflections on some surfaces and to darken a blue sky. The most widely used type, the circular polarizer, has two glass elements. Depending on the angle of the light, you can increase or decrease the polarizing effect by rotating the front element.
Polarizers are effective for both color and black and white photography. They can add drama to a sky, clarity to an object in water, and saturation to foliage in a landscape. As with protection filters, look for multi-coated polarizers with high-quality mounts. Keep in mind that polarizers are dense and will usually absorb two stops of exposure.
Since polarizers tend to be relatively expensive--up to $250 for a 72mm mount--you may want to buy the size for your largest diameter lens, then purchase cheaper step-down rings to mount the filter on your other lenses. But I like to have a polarizer for each of my major zooms.
Neutral Density filters
For photographers who like to shoot at wide apertures or use slow shutter speeds, even in normal daylight, neutral density filters are a valuable asset. They come in two basic types: single density and faders.
Single-density ND filters are commonly available in the following options:
ND.3 = 1 stop exposure adjustment
ND.6 = 2 stops exposure adjustment
ND.9 = 3 stops exposure adjustment
ND1.2 = 4 stops exposure adjustment
You can buy them individually or in a kit. Kits typically run $100 to $200.
The second type, variable neutral density filter, sometimes referred to as "fader ND filters," are often seen in ranges of 2 to 8 stops of exposure adjustment. You choose the density by rotating the outer ring of the filter. I've seen faders as cheap as $35 and as expensive as $350.
What's best for you?
Outdoor and event photographers should consider a high-quality protection filter when working in the field. If most of your work is in the comfy confines of a studio, adding an extra layer of glass shouldn't be necessary.
Polarizing filters are particularly handy for landscape artists. I also like to have one in my camera bag to help me tame reflections when working in contrasty light.
And if you like to shoot at wide apertures for shallow depth of field, or want to slow the shutter for a soft, flowing-water effect, then ND filters are certainly worth the price. Videographers also are big fans of ND filters to help them control depth of field when working in bright conditions. In a pinch, you can use a polarizer to help reduce light to the sensor, since it absorbs two exposure stops too.