The Chrosziel 130:117mm Step Down Ring is a precision-machined lens accessory designed to adapt lenses with a large front thread diameter to accept filters with a smaller diameter. Specifically, this ring enables a lens with a 130mm filter thread to utilize filters sized for a 117mm thread. Constructed from high-quality aluminum, it features precise threading on both the male (130mm) and female (117mm) sides to ensure a secure, wobble-free fit without interfering with the optical path or causing vignetting. This adapter ring is an essential tool for cinematographers and photographers who own large, high-end lenses but wish to utilize a collection of smaller, more common (and often more affordable) filters, such as neutral density, polarizing, or special effect filters.

The ring is engineered to exacting tolerances to maintain perfect lens and filter alignment, which is critical for avoiding optical issues and ensuring the filter functions as intended. Its slim profile minimizes the addition of extra length to the lens assembly, helping to maintain balance and avoid interference with lens hoods or matte boxes where possible. The use of durable, lightweight aluminum makes it robust enough for professional field use while keeping the overall kit weight manageable. For professionals managing a diverse set of cinema or high-end photo lenses and filters, the Chrosziel 130:117mm Step-Down Ring provides a cost-effective and practical solution to maximize filter utility across different lens systems, enhancing system flexibility and creative options.