I have to admit, I was a late starter to the lens filter game. Back in the film days lens filters were the norm, but with the advent of digital it initially felt like all the tricks photo filters could perform could be done in software. Oh, how wrong. It took some time to get up to speed, testing out different filter types, seeking advice and guidance, until now, years later I can’t live without them.
Like many photography processes, the more you can get right in camera the better your photography skills in the long run. This also applies to photo filters. Yes, you can replicate the effects in software to an extent, but the results will never be as good, especially straight out of the camera. If you’re unfamiliar with what a lens filter is, its a square or circular piece of glass that you fit or screw on in front of your lens. The filter will affect the light coming into the lens and change the look of an image depending on which filter you choose. With this in mind, we will go over some of the most common lens filters which can’t be easily replicated in software, and how and why they are used.
UV filters were commonplace back in the film days. Film was sensitive to ultraviolet light, so they were used on the front of many lenses. Digital cameras do not have this problem, but they are still used as protection for the front of a lens.
Some may argue that having a UV filter on a digital camera lens can reduce image quality. This is possibly true if you use cheap filters in the first place, but like any type of filter, it’s good practice to buy the best available even if it means saving up the pennies for a little longer. The Hoya Pro range are a good choice and it’s always better having some sort of lens protection so in the worst-case scenario, busting a filter is preferable to breaking the front of a very expensive lens. You’ll need to check the filter size on the front of your lens to buy the right size.
A polarizing filter essentially reduces the amount of reflected light going into the lens. Uses are for cutting down glare from water, darkening the sky, reducing the reflections from glass, such as on a car windshield, reducing atmospheric haze and reducing the contrast in an image. This is a commonly used filter for landscape photography and car images.
There are two types polarizing filters, linear and circular. The circular version is the most common as it doesn’t interfere with autofocusing on digital cameras. The linear type is if you don’t mind manually focusing and exposing your images. The circular version turns to select different levels of reflected light.
A neutral density filter essentially reduces the amount of light entering the lens. This will provide slower shutter speeds that wouldn’t be possible even with the lens wide open. These type of lens filters are a favorite of landscape photographers to get that blurry water effect. Without an ND filter, an image can be overexposed, blowing out the rest of the image. They are also used to get shallow depth of field in very bright conditions. Blocking a few stops of light can give you the leeway to shoot with any aperture you like.
ND filters come in different stop settings. The larger the stop number means the darker the filter and the more reduction in light. ND filters can range from one-stop up to 15 stops for some filters.
Graduated Neutral Density (GND)
Neutral density filters reduce the light across the whole image, while Graduated neutral density (GND) filters affect only part of the image. GND filters reduce the light in part of the image where it may be too bright, such as an overly bright sky when you have a well-exposed landscape. The filters are mostly dark at the top and clear at the bottom to even out the dynamic range in an image. There are also different types depending on the effect you want. The transition from dark to light and how soft the gradient are all available. Softer gradients are useful for complicated horizons while hard edge gradients work well with our hard lined horizons, such as with the ocean.
Arguably, the same effects can be done in software, like with high dynamic range (HDR) images, where you take three or more shots at different exposure levels and use software to clump them together. Photoshop and Lightroom have graduated filter tools, but there’s nothing like getting it right in camera.
Warming, Cooling, and Miscellaneous Lens Filters
These filters are optional, as the same effects can be reproduced in software. Warming and cooling filters were used to alter the white balance back in the film days, but RAW processing has covered this ground in post-editing software. The same can be said for graduated color filters, which just like Graduated neutral density filters only affect part of the image. These can still be effective to bring out certain colors in parts of an image, especially if you want a certain look. Hoyarex and Hoya are good brand choices for graduated colors.
It can be very easy to dismiss lens filters, especially with so much horsepower with modern photography software. However, the filters listed above can give you endless amounts of playing time and creativity. Try to buy the best quality filters you can afford, then go out and shoot some in a range of settings. In some scenarios, you will find that certain filters become indispensable and give you a certain look straight out the camera, which isn’t always as easy to replicate in software. A good quality UV filter is recommended for any expensive lens and may inadvertently start to you down your own filter collection.