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