ND Filters and CPL Filters: Why, How, and When To Use Them

Filters. You’ve heard of them, but what are they and what do they do?

Some photographers often don’t want to overcomplicate their setup any further than what is necessary. However, for those wanting to excel their expectations and forward their hobby into an actual profession, CPL and ND filters have the potential to turn otherwise standard photographs into something much more mesmerizing and dynamic. While both the CPL and ND filters perform different tasks and functions, each have the ability to give the photographer more control over what appears in your final product.

So, what even are CPL and ND filters and what do they do? And why are we talking about them? These questions are valid concerns and pose an interesting take on elevating our photography level(s) from amateur to professional. 

I’m here to discuss what they are, what each does when to use them, and my personal opinion/review on why I'd use them for my own photographic needs.

What’s a CPL Filter?

A CPL filter – which stands for circular polarizer/linear – is a glass attachment that can reduce the glare from reflected surfaces.

How does it help? Polarized light comes from light that has been reflected off of something. Can come from light reflecting off an alpine lake, reflections from a coffee shop window, or even light reflecting off moisture and pollution in the atmosphere. Polarized light is made up of scattered light rays and is something you don’t want in your shot. The CPL Phone Filter filters out this polarized light, leaving you with an awesome image that you can’t replicate post production. Bluer skies, greener trees, and super sharp clarity in your final image.

Features and Compatibility for Moment’s Antiglare CPL Filter:

• Premium fused silica optical glass for supreme clarity
• Advanced 16 layer optical coatings
• Knurled grip texture for more control and easy removal from lenses
• Stacks with fixed NDs, Moment Cinebloom, or UV Filters
• Smooth rotation ring for precise polarization adjustment
• Available for standard camera lens sizes 58mm - 82mm

Of course I work for Moment and believe we make top-quality products. I’m constantly astounded by the perfectionistic tendencies our gear team commits to, and the many hours of hard earned beers it takes to get there. However, I’m a very non-technical photographer; I tend to steer away from unnecessary gadgets and gizmos, filters included. When I was asked to create photographs with our new CPL, I sighed in disbelief. “Me, really?”, I pondered. Nonetheless, I accepted the challenge and bribed my best friend, Eunice Beck, to gander around Arizona’s famous Canyon Lake for sunset. We packed our to-go coffees and tea, strapped our beloved cameras around our neck, and drove an hour East to a place where reflective surfaces and sunny skies cover the atmosphere.

Upon initial reaction, I didn’t quite understand the point of such a tool. I threaded the filter on my lens before looking at the LED screen, and noticed crisp detail in the water and skies (DUH, Natalie, where you’re supposed to!), but wasn’t taken back. However, I immediately gasped once I took off the filter, kept the same camera settings, and truly saw the difference it made having it on versus not at all. The skies without the CPL were vastly overexposed, had little to no detail, I could barely make out the true color of the sky, and the foreground’s shadows were muddier than desired. The AntiGlare CPL filter made it so that the image’s dynamic range was much crisper and clearer than what your eyes can see; almost like having the classic, juicy dynamic range of an iPhone. See below for a side by side difference.

What’s an ND Filter?

I’m sure you’ve heard me tout the benefits of using an ND filter before in previous articles… like sunglasses for your camera, they give you ultimate control over the light hitting your sensor, and that means slower shutter speeds, giving you smooth motion in your clips and more color in those sunset shots.

What does it do? It lets less light in so you can do longer exposure shots during the day. If you have taken a landscape shot before you know that your sky is either too bright or your foreground too dark - because you’re choosing between sky and foreground on what’s going to be properly exposed.

Moment’s phone filter system uses the same bayonet design on the M-series cases you love. Simply pop the 37mm Filter Mount onto your photo case and you’re ready to shoot with any of our 37mm filters.

Features and Compatibility for Moment's ND Filter

• Featherlight (TM) Construction
• 37mm
• Cinema quality, shatterproof glass
• The neutral color and incredibly sharp
• Low 1.46 refractive index glass
• Proprietary optical coatings

When To Use Lens Filters

There are a multitude of scenarios when one might want to use a CPL or ND filter, as both excel in different areas of expertise. Let’s narrow down to a handful of opportunities that you’re most likely to encounter during your day-to-day.

For a CPL filter:

Removing Glass Reflections: A common first mistake people might notice when starting out in photography is how difficult it can be to take a photo from inside of a window or car door. A polarized filter hones in on the ability to reduce any unwanted streak of light or milky blurs that get in the way of your shot. It can also do the same for reflected light on water surfaces.

Make the Blues More Blue: Nothing ruins your landscape shots more than an overexposed sky. Forebode a sense of tension and mood and darken the sky using a CPL filter, you’ll notice just how much more of a dynamic range you’ll produce.

Remove the Haze: If you’re hoping to make a specific color more vibrant in its detail and hue, then a CPL filter is an excellent choice to do so. See every detail of the leaves on a tree without the unwanted haze coming from the sun.

For an ND Filter…

Long Exposures: Time to go manual mode! This is one of the more common ways to use an ND filter, as it commonly produces a hazy motion blur in the background of an action shot or milks the moving water in a waterfall scene. Stack additional ND filters for a more groundbreaking affect.

Action Shots: Reducing the amount of light entering the lens allows the photographer to select unique combinations of aperture, exposure time, and sensor sensitivity that would otherwise create an overexposed image. Action shots with an ND filter allows the subject to stay tack sharp without unwarranted streaks or flares.

Overall Verdict:

Both are awesome and both provide different functions, so I’d say buy both if you can.

Can you photograph waterfalls without an ND filter or capture the sky without a CPL filter? Absolutely! However, using either will pose as less of a challenge with either and coat your phone or lens with an exceptional cover made to save your camera from scratches or dust. They really are a great tool for photographers and I’m stoked we have these bad boys in our shop.

The most convenient part? You don’t need a Moment Lens to attach one or either of these filters to your phone. Moment used to make it so that you had to have a $100 lens in order to attach it, but no more. Simply purchase a filter mount and directly attach the filter onto your phone by turning it 90 degrees in their slots. They don’t work with the selfie camera yet (darn), but who needs that anyway?!