A Filmmaker's Guide to Camera Filters

Hey there, filmmakers! Let’s talk camera filters – those magical pieces of glass (or resin) that protect your investment in your lenses and can transform your shots in ways you might not have imagined. While they are generally sold separately from a lens, they should not be forgotten when purchasing your lens or planning for your shoot.

Whether you're a seasoned pro or just starting, understanding camera filters can be a game-changer for your filmmaking. Let’s dive in!

What Are Camera Filters?

Camera filters are attachments you screw onto the front of your lens. They alter the light entering the lens, impacting the final image.

In addition to protecting your camera lens, they can help you achieve effects in-camera that might be impossible or tedious to replicate in post-production.

Read: How to Make Your Own Color Filters at Home

Types of Camera Filters

For new cinematographers, understanding camera filters is crucial. Polarizing and UV filters, in particular, should be standard purchases when you buy a camera lens. The reason lenses don’t come with these critical filters already attached is to give you, the filmmaker, the flexibility to choose the specific filter that best meets your creative goals.

A good filter can significantly impact image quality, from reducing glare and reflections to enhancing colors and protecting your lens (which you may have spent thousands of dollars on). Let’s explore the different types of filters and how they can elevate your filmmaking.

1. UV Filters: Originally designed to block ultraviolet light, protecting your lens from dust, scratches, and smudges is their main job now. Protect your financial investment with a UV filter!

Read: Are Clear UV Filters a Pro or a Con for Expensive Lenses

2. Polarizing Filters: Reduce reflections and glare from non-metallic surfaces (like water and glass), enhance colors, and increase contrast. You need them for outdoor shoots, but many argue you should always keep a polarizing filter on your lens to minimize glare in any environment.

Be aware, using a polarizer reduces the light entering the lens by 1.5 to 2 stops, so you'll need to adjust your exposure settings to compensate.

Read: What does a Polarizing filter do? Before & After Comparisons

3. ND (Neutral Density) Filters: Reduce the amount of light entering the lens without affecting the color. Essential for shooting in bright conditions with a wide aperture or slow shutter speed. Think of them as sunglasses for your lenses.

Any time you are planning to shoot outdoors on a sunny day, you should expect to take a ND filter, or possibly a variable ND filter

Read more about variable vs. non-variable ND filters

4. Graduated ND Filters: Like ND filters, but the effect is gradient, darker at the top and clear at the bottom. If you're planning on shooting out in wide-open landscapes, graduated ND filters are great for balancing the exposure between the sky and the landscape.

5. Color Filters: These can add a tint to your footage, helping set a mood or correct color in specific lighting situations where color correction lighting gels are less practical.

Read: Filter Guide: Have Digital Cameras Made Coloured Filters Obsolete?

6. Special Effects Filters: These include star filters, which create starburst effects from light sources, or diffusion filters that soften your image for a dreamy look.

Common Brands at Different Price Points

Filters come in all shapes, sizes, and price ranges. I do recommend putting the same attitude of investment into your filters as you do the lens itself - it would be a shame to cancel out the qualities of quality glass with a cheap filter - but that isn't always fiscally possible.

Camera filters should not be forgotten when purchasing your lens or planning for your shoot.

Here are some reputable camera filter brands, at everyone's price point:

Budget-Friendly: Tiffen and Hoya are great for beginners or those on a tight budget. They offer solid quality at affordable prices.
Mid-Range: B+W and Heliopan provide excellent quality without breaking the bank. They’re a good choice for serious enthusiasts and semi-professionals.
High-End: For the pros, brands like Schneider and Lee Filters are top of the line. These filters are renowned for their exceptional quality and durability.

Finding the Right Thread Size

Purchasing the correct thread size for your lens is necessary for your filter to fit on the lens without an adapter.

Read about camera filter adapters

Camera filter adapters are handy tools that allow you to use filters on lenses with different thread sizes. They screw onto your lens and create a new thread size, enabling you to use a single filter across multiple lenses. This is a cost-effective solution, saving you from buying multiple filters for each lens size.

The thread size is usually indicated on the front or side of your lens and is measured in millimeters (mm). It’s often marked with a diameter symbol (Ø). For example, if you see “Ø67mm,” that’s your thread size.

No symbol? Check the lens cap or the inside of the lens cap – it’s often marked there.

The Role of Filters in Creative Choices

Achieving cinematic effects in-camera rather than relying on color-grading and other post-production techniques can be a game-changer.

Doing it in-camera means you're capturing the look you want right from the start, which saves time in editing and ensures consistency across your shots. Plus, it often looks more natural and authentic, giving your film that professional, polished feel straight out of the gate.

Effects recorded "in-camera" often look more natural and authentic than color-grading or adding effects in post-production

So, mastering the use of filters and other in-camera techniques can really elevate your filmmaking to the next level. Let’s break down how camera filters can be instrumental in shaping the aesthetic of your film:

Setting the Mood: Camera color filters come in various types, including warming filters that add a cozy, golden tone to your shots, and cooling filters that give a blueish tint for a more detached or uneasy feel.

There are also color correction filters that help balance the colors in different lighting conditions, ensuring your footage looks natural and consistent.

Enhancing Reality: Polarizing filters can make skies pop and water look crystal clear, immersing your audience in the world you’re capturing.

Types of Polarizing Filters

There are two main types of polarizing filters:

1. Linear Polarizing Filters: These reduce glare and reflections, and enhance color saturation, but can interfere with autofocus and metering systems on modern cameras.

2. Circular Polarizing Filters: Typically have abbreviations engraved on filter ring of CIR PL or CPL. These offer the same benefits as linear polarizers but are designed to work with autofocus and metering systems, making them more suitable for modern digital cameras.

If you want to shoot nature, use a circular polarizer for best results.

A Deeper Dive into Circular Polarizers

Circular polarizers have two parts: a linear polarizer that handles the main polarization, and a quarter wave plate that rotates the light after it passes through the linear polarizer and before it enters the camera lens. This rotation is crucial because it maintains the light's orientation in a way that ensures the autofocus and metering systems in modern cameras receive consistent and predictable light, allowing them to function correctly for accurate exposure and sharp images.

Further Reading: When NOT to Use a Polarizing Filter

Creating Visual Styles: Using ND filters, you can shoot with a wide aperture even in bright daylight, achieving that cinematic shallow depth of field look.

Read: How to Capture a Shallow Depth of Field in Sunlight

Balancing Light: Graduated ND filters help manage high contrast scenes, like a bright sky and dark foreground, keeping details in both areas without overexposing or underexposing parts of your image.

Special Effects: Want a dreamlike sequence? A diffusion filter can soften your image, giving it an ethereal quality. Or maybe a night scene where streetlights turn into starbursts? A star filter has got you covered.

Key Takeaways

Understanding camera filters is essential for filmmakers and photographers alike. From polarizers that enhance colors and reduce glare to neutral density filters that control light exposure, each type serves a specific purpose in achieving desired visual effects.

Whether you're aiming for cinematic depth of field, color correction, or protecting your lens, choosing the right filter can elevate the quality and creativity of your images. By mastering these tools and their applications, you can enhance your storytelling and capture stunning visuals straight from the camera.

Happy filming!

Check out the rest of the Choose the Best Lens for Your Project series