The ARRI Signature Primes present a versatile and customizable option for filmmakers. Among the 16 primes in the series, the 125mm T1.8 stands out, offering compatibility with all image sensors up to full-frame, large-format. This lens is characterized by its organic imagery, appealing bokeh, subtle flaring, and a fast maximum aperture, facilitating a shallow depth of field. The 125mm Signature Prime provides a gentle softening of the large-format aesthetic, delivering natural skin tones, crisp blacks, and a smooth focus fall-off that enhances the subject against its background. Notably, the lens features a magnetic rear net holder, allowing users to attach stockings, nets, or voile for custom diffusion and various effects. The eleven iris blades contribute to creating smooth and rounded bokeh, while the telecentric design minimizes breathing. Constructed with magnesium housings and aluminum gear rings, each Signature Prime is both lightweight and water-resistant. The focus marks in feet make it user-friendly, and anti-reflective coatings, light baffles, and light traps work together to minimize internal barrel flare. The lens also boasts an integrated LDS-2 lens data system, which is backward-compatible with ARRI's LDS-1 and communicates seamlessly with Cooke's /i Technology. Overall, the ARRI Signature Prime series, exemplified by the 125mm T1.8, combines cutting-edge technology with durability, making it an ideal choice for filmmakers seeking high-performance, adaptable lenses.