BW Photography and Filters(4541.762 Computational Photography)

Jehee Lee

Seoul National University

Black-and-While Films

• Most of today’s BW films are panchromatic– Sensitive to blue

Orthochromatic film Infrared film

Panchromatic film

Color Filters

Filters for BW films

• Yellow– Absorbs ultraviolet and blue-violet– Darkens blue sky– Balances panchromatic film to match normal visual

response

• Deep yellow and red– Lightens yellow and red subjects such as flowers– Darkens blue water and sky

• Yellowish green– Outdoor portraits– Balances values in tungsten-lit scenes

Filters Also Used With Color Films

• Skylight or ultraviolet (UV)– Little or no effect with BW film– Protect lens surface from damage

• Neutral density (ND)– Absorbs equal quantities of light from all parts of the

spectrum– Wider aperture or slower shutter speed

• (Circular) Polarizer– Absorbs light waves traveling in certain planes

relative to the filter

Polarizing

Infrared film