Camera Lens Filters Explained: UV, CPL, ND, Star & More

What They Actually Do—and Which Ones Deserve a Spot in Your Bag

Why Bother With Filters?

If you’ve ever scrolled Instagram and wondered why someone else’s shot looks cleaner, punchier, or more dramatic than yours, you’re not alone. After a decade of pro work—and almost as long wrestling with imposter syndrome—I’ve wasted plenty of money on gimmicky glass. Here’s the distilled truth: a handful of filters can transform your photos and protect your kit, while the rest are just dead weight.

Below you’ll find the six most common lens filters, what they’re meant for, when (or if) you should use them, and my verdict on whether they’re worth buying in 2025.

1. UV (Ultraviolet) Filter

Back in the film days:

Job: Cut atmospheric haze and block UV light.
Reality today: Digital sensors already handle UV; image-quality gains are basically nil.

Why I still keep one on:

Cheap “insurance policy” against scratches, dust, salt spray, or the occasional toddler fingerprint.

Buy if: You want peace of mind for the front element of every lens.
Skip if: You shoot carefully and would rather save every last pixel of sharpness (even a top-tier UV adds a micro-contrast hit).

2. FLD (Fluorescent Light Daylight-balance) Filter

Original problem solved: Neutralize the green cast of old fluorescent tubes by adding magenta.

Digital reality:

White-balance sliders make FLDs redundant.
On most modern cameras they just turn your image…purple.

Verdict: Leave it in the history books (or the clearance bin).

3. CPL (Circular Polarizer)

What it does:

Eliminates glare and reflections on water, glass, or wet foliage.
Deepens blue skies and makes colors pop.
Works by rotating the filter until glare disappears—like a magic dial for saturation.

Essential for:

Landscapes with water or leaves.
Architecture and interior shots through windows.
Anyone who’s ever cursed lens flare on a bright day.

Must-have rating: ★★★★★ – if you shoot outdoors, this belongs in your everyday kit.

4. ND (Neutral Density) Filter

Think of it as sunglasses for your lens.

Purpose: Blocks a fixed amount of light so you can use slower shutter speeds or wider apertures in bright conditions.
Common uses:
- Silky waterfalls or ocean waves (long exposure).
- Daytime portraits at f/1.4 without blowing highlights.

Worth it? Absolutely—just match the ND strength (e.g., ND8, ND64) to your creative goal.

5. Variable ND

The same light-blocking power—on a dial.

Twist to adjust darkness in real time.
Perfect for video, where you need to hold a cinematic 1/48 s shutter as clouds drift or the sun ducks behind buildings.

Trade-offs:

Slight risk of “X-pattern” vignetting on ultra-wide lenses.

Pricier than fixed NDs—but one good variable often costs less than a full fixed-ND set.

6. Star (Cross-Screen) Filter

Pure style.

Adds starbursts to every point of light: street lamps, stage lights, headlights.
Choose your flare: 4-point, 6-point, 8-point, etc.

Best for:

Night-city scenes, concerts, holiday lights, or whenever you want an extra dash of drama.

Pro tip: Use sparingly—what feels “cinematic” at first can look kitschy fast.

Quick-Reference Buy List

Filter	Skip	Maybe	Buy
UV		✔️ (only for protection)
FLD	✔️
CPL			✔️
ND (fixed)			✔️
Variable ND		✔️
Star		✔️ (creative-only)

Final Thoughts

Not every filter is worth the hype, but the right glass can level-up your photography overnight—whether you’re killing glare, protecting a pricey front element, or spinning creative light trails across a city skyline.

Remember: the horizon may be dark, but beyond the shadow lies your story.

Happy shooting!