The American Society of Cinematographers (ASC) is an educational, cultural, and professional organization. It is not a labor union, and it is not a guild. Membership is by invitation and is extended only to directors of photography and special effects experts with distinguished credits in the film industry. Not all cinematographers can place the initials ASC after their names. ASC membership has become one of the highest honors that can be bestowed upon a professional cinematographer, a mark of prestige and distinction.