Shaped optical film

A curved optical film generally lying in a base plane and having an average thickness of less than about 500 microns, and an average optical absorption of less than about 70% for substantially unpolarized substantially normally incident light in a predetermined wavelength range extending at least from 450 nm to 600 nm,

• a first cross-section of the optical film in a first plane perpendicular to the base plane having an actual first length AL1, a projected first length PL1 on the base plane, and a first stretch ratio S1 defined as (AL1−PL1)/PL1,
• a second cross-section of the optical film in a second plane perpendicular to the first and base planes having an actual second length AL2, a projected second length PL2 on the base plane, and a second stretch ratio S2 defined as (AL2−PL2)/PL2, 0.01<S2<0.7S1,
• the optical film having a maximum thickness variation in a range from about 0.05S1 to about 0.8S1 along each of the first and second cross-sections.

A stretched and shaped optical film stretched and shaped along at least mutually orthogonal directions and having an average optical absorption of less than about 70% for substantially unpolarized substantially normally incident light in a predetermined wavelength range extending at least from 450 nm to 600 nm, such that when the optical film is placed on a flat surface,

• a first cross-section of the optical film in a first plane perpendicular to the flat surface has a maximum deviation D1 from a straight line connecting opposing ends of the first cross-section, the first plane chosen to maximize D1,
• a second cross-section of the optical film in a second plane perpendicular to the first plane and the flat surface has a maximum deviation D2 from a straight line connecting opposing ends of the second cross-section, the second plane chosen to maximize D2, 0.1D1<D2<0.7D1,
• the optical film having a maximum thickness variation of less than about 15% along each of the first and second cross-sections.