Which Single Filter Would You Carry?

If you could bring only one filter, which one would it be? For me, it would be an ND64 filter.

Why Choose ND64?

Before diving into ND64, let’s first understand ND8, ND16, and ND32. ND stands for Neutral Density, which means it reduces light transmission compared to a clear lens. This is why ND filters appear dark—they help block excess light, allowing for better exposure control without adjusting the aperture.

To simplify, think of ND filters like a multiplication table:

• ND8 ≈ 3 Stops
• ND16 ≈ 4 Stops
• ND32 ≈ 5 Stops
• ND64 ≈ 6 Stops

Since ND64 reduces 6 stops of light, why is this number ideal instead of other options ranging from 1 to 20 stops? Here’s why:

1. Expanding Dynamic Range

Modern cameras have a dynamic range of around 15 stops, approaching the human eye’s 20-stop range. However, in real-world usage, only about 10 stops are truly usable. In a high-contrast scene, where the brightest point is +5 stops and the darkest is -5 stops, an ND64 filter (6 stops) helps expand the range. For example, under harsh sunlight, this makes 5+6 = 11 stops, ensuring balanced exposure without exceeding what the human eye can perceive.

2. ND64 Maintains Autofocus Efficiency

ND64 isn’t too dark, so it still allows easy focusing. In contrast, ND1000 lets only 0.1% of light through, making focusing challenging—especially during sunrise or sunset, similar to wearing ultra-dark sunglasses in low light.

3. Retaining Depth of Field Without Compromising Shutter Speed

Imagine shooting a runner and wanting a panning effect while keeping a wide aperture (f/2.8) for background blur. Under bright daylight, shooting at 1/200s or 1/100s with an open aperture is nearly impossible—even with ISO 50. An ND filter allows you to maintain control over the aperture, making it a game-changer.

4. Creating Stunning Long-Exposure Shots

Long exposure photography is where ND filters truly shine. From creating silky water effects to capturing vibrant streetlights on winding roads like Thẩm Mã Pass or Tà Nung, an ND filter transforms a scene. Even clouds become surreal with prolonged exposure.

5. Eliminating Crowds in Photos

Visiting a crowded tourist spot? An ND filter allows you to remove people from the frame by using a 30-second to 1-minute exposure. Moving subjects disappear, leaving behind an empty scene. This technique, known as shutter speed control, can make a busy street appear “bustling” with light trails in a short exposure or “empty” with a longer exposure.

6. Stacking ND Filters for Greater Light Reduction

ND filters can be combined for increased effect. For instance, stacking ND64 + ND32 results in 11 stops of light reduction, offering more creative flexibility.

7. Converting ND Square Filters into GND Filters

Square ND filters typically cover the entire lens, but when paired with a holder and gradually adjusted, they can act as a GND (Graduated Neutral Density) Hard filter—perfect for seascape photography when a dedicated GND is unavailable.

8. Versatility and Accessibility

ND filters come in various forms—circular, square, rear-mounted, and at different price points. They’re widely available and borrowable, but high-quality filters can be quite expensive.

These are my 8 personal reasons for always carrying an ND filter on my travels. What about you? Share your thoughts below!