Knowledge

A layman’s guide to lens filters

Published on May 16, 2014 under Photography

Camera lens filters

Summer is approaching. It’s a time for sun, warm weather, outdoor events, and especially travel. While we live in an age of the smartphone camera, some of us still love to lug our more powerful DSLRs out in our quest for beautiful photography. Beyond our camera bodies and lenses, one important tool in our bags is the filter.

Now I’m not talking about Instagram filters here, but more what looks like circular glass plates you place on the front of a lens. Their purpose is as you get with apps like Instagram, to modify what you shoot for a desired effect.

Now if you’ve never touched a filter in your life, don’t fret. Today I want to run you through the basics, and give you a grasp of a few filters you might want to purchase for your lenses.

The UV Filter

Photo examples of a UV Filter in action
Click to enlarge

Out of any filter you could ever purchase, a UV filter should be your priority. I mentioned before, the most common use of a UV filter is mainly as protection for your expensive lenses. Scott Kelby told long ago of how he dropped a lens once on the concrete, and his inexpensive UV filter took the damage, thus saving his lens. I still highly advise you buy a UV filter for each lens you own.

Beyond protection, UV filters do serve an actual photographic purpose. When shooting in the sun, even when it’s not on you, you’ll still see what looks like a cloudy haze on your backgrounds. So that shot of an island landscape will suddenly seem like there is a very light fog on your background horizon. A UV filter will sharpen the image and fix the problem.

The Polarizing Filter

Photo examples of a Polarizing Filter in action
Click to enlarge

Probably one of the most popular filters to own, a circular polarizer is an ideal tool when you’re shooting landscapes, water, and even windows. The filter itself looks like any camera lens filter, only dark, and seemingly you can rotate it. Looking through the lens, it appears like a gradient where part of the view is bluer than the rest.

The primary use for a polarizer is to remove glare and reflections. Imagine you’re trying to take a photo of your friend’s storefront, but you only see bright reflections on the windows. Use a polarizer and magically they’ll disappear, allowing you to see inside of the store. The same effect happens when you try to shoot water, like a lake or pond. An added bonus is you can use a polarizer to make the sky bluer, which helps on those sunny days when the sky appears practically white.

The Neutral Density Filter

Photo example of a Neutral Density Filter in action
Click to enlarge

The best way I could describe a Neutral Density (ND) filter would be “sunglasses for your lens”. It’s basically a darker lens that allows you to keep the shutter open longer without overexposing your image.

So why would you use one? Maybe you are out on a bright day, and it seems you’re getting overexposed images even when you put your shutter speed at its fastest setting. Or you want to open the shutter for a long period, to get that “ghostly” effect of people moving through the scene, but the daylight limits how long you can keep the shutter open. An ND filter is open for many uses. It really comes down to your imagination.

ND filters also come in different levels of darkness. I’d usually suggest buying a medium-level, and only investing in other levels if you see a need. There is also a graduated ND filter, which is much like a circular polarizer in terms of a graduated setup. A primary use would be if you would like to darken the sky, but not the ground level.

Color filters

Color filters

These are purely optional to own, as I honestly do not own any. They are as they claim to be. Simple filters that dominate your shot with one color.

So why use them? There could be a number of specialized reasons. Do you shoot in black & white? Color filters would allow you to alter how your shots appear, since the spectrum conversion would be modified by the color you choose.

You can also use color filters to add warmth or coolness to your photos. More often than not, photographers will use a blue filter when shooting in tungsten light. The end result is a balanced color. Again, it really comes down to your imagination.

Why not use Photoshop?

That is a good question, and I’d agree when it comes to the color filters. You can easy warm or cool a photo in Photoshop, as well as alter it. However, when it comes to the benefits of a UV filter, Polarizer, or ND filter, you can do much better for yourself by getting these changes/corrections done in the shoot.

I’ve done many kinds of corrections in Photoshop, but using filters in the shoot has made it where I did not have to do much post-production work. Plus, some things can’t be corrected, like an overexposed photo or glare and reflections. I personally think whether you’re an amateur or professional, you should have those three filters in your arsenal.

Do you use glass filters in your photography? Why or why not?

Tags: camera, lens, filter, polarizing, uv, neutral density

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