Lenses The Art of Focus Compound Lens Diagram A lens is made up of multiple lenses Two Basic Types of Lenes Converging lens gathers light Diverging lens scatters light Types of Single Lenses Biconvex (double convex) Plano Convex Convexconcave Meniscus Planoconcave Biconcave (double convave) Double Convex Lens Converging lens gathers light Center bloated A convex lens is one in which the center is wider than the ends Double Concave Lens Diverging lens scatters light Center caved-in A concave lens is wider at the edges than at the middle Concave lenses are primarily used in eyeglasses for people who are nearsighted Focal Length Ultra wide angle is less than 20mm long Wide angle is 24mm to 45mm long Normal (for 35 mm film) is 50mm long Short telephoto is between 55mm & 135mm Long telephoto is between 200mm & 300mm Ultra long telephoto is over 400 mm long Macro lenses come in varying focal lengths Fisheye lenses are Ultra wide angle lenses Wide Angles Emphasis on foreground 15 mm Fisheye Ultra Wide Angle Lens 24 mm Wide Angle 35 mm Normal What the eye sees 35 mm film standard Normal Lens 50 mm Normal for 35mm negative What the human eye sees Telephotos Emphasis on background Squishes depth together Makes things look closer Short Telephoto 135 mm Short Telephoto 200 mm Long Telephoto 300 mm Super Long Telephoto 400 mm Super Long Telephoto 600 mm Zooms Older ( s) lenses have soft spots that do not focus Zoom lenses have variable focal lengths Ultra Wide Angle Wide angle Mid-range Long Wide Zoom mm mm Midrange Zoom mm Long Midrange Zoom mm Long Zoom mm Macro Close-up lens Very shallow depth-of-field Macro Lens 100 mm 105 mm 24mm 50mm 85mm 200mm Basic Focal Lengths