Specs

• m43, X mount, E mount, EF-M Mount Lens, max APS-C Format
• Aperture Range - f/1.4 to f/22
• 8 elements in 7 groups, 3 Aspherical Elements, 1 ED Element
• Ultra Multi-Coating
• Internal Focus; Manual Focus Design
• Non-Rotating 58mm Filter Mount
• Rounded 9-Blade Diaphragm
• $499 - http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=21mm+F1.4+Samyang+

This 21mm f/1.4 is a standard wide-angle lens offering an equivalent focal length of 31.5mm to 42mm, depending on mount choice. The bright f/1.4 maximum aperture is well suited to working in a wide variety of lighting conditions and also offers selective focus control to emphasize specific subjects in the frame. A manual focus design is employed here again, along with an internal focus system and non-rotating 58mm front filter mount to both maintain the overall length of the lens during use and prevent filters from rotating when focusing. One extra-low dispersion element and three aspherical elements are incorporated into the optical design to limit color fringing and various aberrations in order to achieve greater sharpness and clarity. The Ultra Multi-Coating has been applied to all elements in this lens, too, and a rounded nine-blade diaphragm contributes to smooth out-of-focus areas when using selective focus techniques.