What Is a UV Filter

A UV filter is a thin piece of clear glass that screws onto the front of your lens. In the film era, it blocked ultraviolet light that could make outdoor photos look hazy or blue.

Today, digital sensors already have built-in UV protection. That means the UV filter’s original purpose — reducing ultraviolet haze — no longer matters.

Yet UV filters are still popular, not for blocking UV light but for protecting the front element of a lens from scratches, fingerprints, and dust.

Why People Still Use UV Filters

Even though digital sensors don’t need UV protection, many photographers still use these filters for peace of mind. The logic is simple: if something hits your lens, it’s cheaper to replace a $20 filter than a $400 front element.

Here are the main reasons people keep a UV or clear filter on their lens:

1. Physical protection: It can prevent small scratches or damage from keys, sand, or bumps.

2. Easy cleaning: It’s safer to wipe dust or smudges off a filter than your actual lens coating.

3. Weather sealing: On some high-end lenses, adding a filter completes the seal and keeps out moisture.

4. Resale value: A lens that’s always had a filter may stay cleaner and scratch-free, appealing to future buyers.

At first glance, that sounds convincing. But there’s another side to the story.

When UV Filters Can Do More Harm Than Good

1. Reduced Image Quality

A cheap filter adds another layer of glass in front of your optics, and not all filters are perfectly clear. Lower-quality filters can introduce:

• Reduced contrast

• Lens flare and ghosting

• Slight softness or loss of sharpness

This becomes especially visible when shooting into bright light or at night. You may notice strange reflections or washed-out highlights caused by internal reflections between the filter and lens.

2. False Sense of Security

While a UV filter can protect from scratches, it won’t save your lens if you drop it hard. In many cases, the filter shatters — and broken glass can scratch your front element worse than the original impact would have.

3. Color Casts and Reflections

Some low-quality filters slightly alter color balance or create visible reflections under artificial light. This is most noticeable in long exposures or when photographing city lights at night.

When a UV Filter Is Actually Useful

There are still a few situations where a UV or protective filter makes sense.

1. Dusty or sandy environments: Beaches, deserts, and construction sites can throw fine grit at your gear. A filter adds a removable layer of protection.

2. Sea spray or mist: If you’re photographing near the ocean or waterfalls, a filter prevents salt or water from coating your lens directly.

3. Snow and rain: A filter can make cleaning easier and prevent water from freezing onto the glass.

4. Resale-conscious shooters: If you plan to sell your lens later, a filter can keep the front element looking pristine.

In these cases, a high-quality, multi-coated filter can be worth it.

Choosing the Right UV Filter (If You Decide to Use One)

Not all filters are created equal. A cheap, uncoated one can harm your image more than it helps your lens.

Look for these key features:

• Multi-coated or nano-coated glass: Reduces reflections and flare.

• High optical clarity: Look for filters made from Schott glass or equivalent materials.

• Brass or aluminum mount: Avoid plastic threads that can get stuck.

• Slim profile: Prevents vignetting, especially on wide-angle lenses.

Reputable brands like Hoya, B+W, and Breakthrough Photography produce excellent filters that maintain image quality.

When to Take the UV Filter Off

If you do use one, there are moments when it’s best to remove it.

• Shooting directly into bright lights: Prevent reflections and ghosting by taking the filter off.

• Working indoors or in controlled conditions: There’s little benefit to keeping a filter on in a studio or at home.

• Using additional filters: If you’re stacking ND or polarizing filters, remove the UV to avoid flare or vignetting.

Treat the filter like a tool — use it when needed, not automatically all the time.

Alternatives to UV Filters for Protection

You don’t need a UV filter to keep your lens safe. There are better, optical-quality options for everyday care:

1. Use a lens hood: It protects your lens from knocks, rain, and flare — all without touching image quality.

2. Keep your lens cap on: Always cover your lens when not shooting. It’s free and effective.

3. Handle your camera carefully: Most damage comes from accidents, not normal use.

A lens hood, combined with basic care, offers better protection than a filter in most cases.

The Lens Resale Value Myth

Some photographers believe always keeping a filter on helps retain resale value. This is partly true — a clean front element does look good when selling.

However, buyers today are more knowledgeable. They care about glass clarity and internal condition, not whether a lens lived behind a filter.

A spotless front element is nice, but minor surface marks don’t affect image quality. You might be better off saving money on filters and investing in good storage and regular maintenance.

FAQs About UV Filters

Should I keep a UV filter on my lens all the time
Only if you’re in a harsh environment. For everyday use, it’s unnecessary and may reduce image quality.

Do UV filters protect against drops
Not really. They can protect from small bumps but won’t save your lens from serious impact.

Do UV filters affect autofocus or exposure
No. They’re optically clear and don’t change focus or brightness.

Can UV filters cause lens flare
Yes, especially in strong sunlight or night photography. Removing the filter often reduces flare.

Is a clear protective filter better than a UV filter
They’re basically the same today. Modern “protective” filters are just UV filters without marketing around ultraviolet light.

Conclusion: Save Money and Shoot Smart

For modern digital cameras, UV filters are no longer essential. They don’t block anything your camera can’t handle, and cheap ones can reduce image quality.

Instead, use a lens hood for physical protection and add a high-quality filter only in challenging environments like the beach or desert.

If you’re careful with your gear, you’ll never miss having one — and your photos will be cleaner, crisper, and free from unwanted reflections.