The first version of the Canon EF 24mm f/1.4L USM lens was released in December 1997. It is a super-fast wide-angle lens designed for full-frame cameras. This lens features a robust optical construction that utilizes Canon's advanced technologies of the time to minimize distortion and enhance image quality. Technical Specifications (First Version): Optical Construction: Consists of 11 elements in 9 groups, including one aspherical element and one UD (Ultra-low Dispersion) element to reduce chromatic aberration. Aperture: Very wide maximum aperture of f/1.4, with 7 aperture blades (diaphragms). Focusing System: Equipped with a ring-type USM motor that allows for fast and quiet autofocus, with full-time manual focus control. Minimum Focusing Distance: 0.25 meters (25 cm), providing a maximum magnification of 0.16x. Filter Size: 77mm diameter. Dimensions and Weight: Weight: Approximately 550 grams (lighter than the second version, which weighs 650 grams). Dimensions: Maximum diameter 83.5mm and length 77.4mm. Performance Notes: According to a review from OpticalLimits, the lens boasts professional L-series build quality with a metal body and utilizes a "floating system" to ensure consistent image quality across the entire focusing range from close distances to infinity.