Use Focal Length Calculator: http://goyolenses.com/focal-length-calculator/ Goyo Optical’s NEW Focal Length Calculator allows you to easily find your effective focal length plus a variety of lenses best suited for your application. Results are sortable by: • Focal Length • Format • Mount • Resolution • Iris Range • Minimum Object Distance (M.O.D.) • Filter Thread Founded in 1976, Goyo Optical Inc. provides High Resolution Industrial Lenses for Machine Vision and CCTV/Security applications. Focusing on excellent quality at an attractive price, Goyo offers more industrial lens designs than any single Machine Vision lens manufacturer in the world.