Hoya HMC NDX4 Filter

Neutral Gray Filter ND X 4:

• Shutter speed extension or aperture opening: by 2 stops
• Apparent sensitivity change: quartering, e.g., from ISO 800/30° to ISO 200/24°
• HMC (Hoya Multi Coated): The multi-coated filters are known for their extremely low reflections on their glass surfaces, which further suppresses stray light and ghost images.
• Filter diameter: 52 mm

Neutral gray filters are often overlooked by many photographers, but they can be very useful in certain situations and produce results that would otherwise be impossible. ND filters (Neutral Density) appear gray and reduce the amount of light reaching the film without affecting color balance. There are four main areas of application for them:

1. They allow for long shutter speeds even with higher sensitivity films to capture movement, such as in waterfalls and streams, fountains, clouds, or moving cars.
2. They enable larger apertures for shallower depth of field, helping to clearly separate a subject, such as a portrait, from its background.
3. They act as if the film sensitivity has been lowered, allowing even high-sensitivity films (i.e., above ISO 400/27°) to be used in bright daylight.
4. They enable correct exposures in bright environments, such as snow and sandy beaches or under extremely bright lighting, even with film and video cameras that have non-adjustable shutter speeds, preventing overexposure.