Urth Polarizing ND64 Lens Filter (CPL) + Plus+ - 39mm

CPL stands for Circular Polarizer, which reduces reflections and enhances colors. ND64 stands for Neutral Density 64, meaning it reduces light by 6 stops (a factor of 64 in light transmission).

Check the number printed on the front of your lens, usually near the lens cap. It will have a circle with a slash through it, followed by a number, e.g., ø39mm. This filter has a 39mm thread size.

No, the ND64 component severely blocks light, making it unsuitable for capturing faint celestial objects. The CPL function can also be detrimental to astrophotography.

Use a soft microfiber lens cloth. For tougher smudges, use a dedicated lens cleaning solution sparingly on the cloth, not directly on the glass.

Urth offers a lifetime quality guarantee on their filters.

While the filter itself doesn't directly interfere with autofocus mechanisms, the significant reduction in light (6 stops) can make it more challenging for some camera AF systems to lock focus in dimmer conditions.

While technically possible, stacking this filter with others, especially on a 39mm thread, is not recommended as it significantly increases the risk of vignetting and optical degradation.

Ensure the outer ring of the CPL is rotated to the optimal position. The effectiveness of polarization varies with the angle between the camera and the reflective surface.

The ND64 filter significantly reduces light. Adjust your camera's shutter speed, aperture, or ISO to compensate for the 6-stop light reduction.

This can occur with ultra-wide-angle lenses. Try zooming in slightly or consider using a filter with a larger diameter if the issue persists.

Ensure the filter is clean and free of smudges. The high-quality glass and coatings minimize these issues, but proper care is essential.