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