Kodak's new Professional Kodachrome 64 and soon to be available Professional Kodachrome 25 are not new emulsions; Kodak selects film from regular production runs, then ages and tests batches until they meet critical color and speed tolerances. The vintage film is then packaged and refrigerated as Professional film. Sharpness, grain, and dye stability should be the same as regular Kodachrome. -- AATA