BW Photography and Filters ( Computational Photography) Jehee Lee Seoul National University

Black-and-While Films Most of today’s BW films are panchromatic –Sensitive to blue Orthochromatic filmInfrared 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