A dielectric resin composition comprising at least one type of epoxy resin and at least one type of cyanate ester which would react with said epoxy resin, together with a metal ion catalyst system, the ratio of the epoxy functional groups of said epoxy resin to the cyanate groups of said cyanate ester being in the range of from 1:0. The display unit superimpose a framing assisting pattern on the moving image to facilitate the framing of the image to be taken. Methods of releasing additives into fluid material are also provided.