| abstract |
An optical compensation film comprising a cellulose ester film is disclosed. In the film, (a) each of photoelastic coefficient C(md) in a mechanical direction and photoelastic coefficient C(td) in the transverse direction of the cellulose ester film is 1×10 −9 to 1×10 −13 Pa −1 and C(md)<C(td), (b) retardation R 0 within the plane of the cellulose film defined by Formula (I) is 20 to 70 nm, (c) retardation R t of the cellulose ester film in a thickness direction, defined by Formula (II) is 70 to 400 nm, and (d) both of a dimensional variation ratio S(md) in the mechanical direction and a dimensional variation ratio S(td) in the transverse direction of the cellulose ester film prior to and after being allowed to stand at ambient conditions of 80° C. and 90 percent relative humidity for 50 hours are − 1 to 1 percent, and |S(md)|>|S(td)|. |