In
Bridgeman Art Library v. Corel Corp. the court held that photographs were "writings" within the meaning of the Copyright Clause and cited
Nimmer on Copyright, which stated that there "appear to be at least two situations in which a photograph should be denied copyright for lack of originality".
Judge Lewis Kaplan considered one of those situations, as described by Nimmer, to be directly relevant, namely that "where a photograph of a photograph or other printed matter is made that amounts to nothing more than slavish copying". A slavish photographic copy of a painting thus, according to Nimmer, lacks originality and thus copyrightability under the U.S. Copyright Act. One rule that the treatise had proposed, known as the
inverse ratio rule, stipulated that a high degree of access would lower the burden of proof for substantial similarity. The rule had initially been endorsed by the Ninth Circuit in ''
Sid & Marty Krofft Television Productions Inc. v. McDonald's Corp.'' (1977), when the court held that the defendants' prior consultations with the plaintiffs regarding their IP had substantively implicated the former parties in copyright infringement. This doctrine was abrogated in
Skidmore v. Led Zeppelin (2020), the Ninth Circuit holding that "the inverse ratio rule, which is not part of the copyright statute ... creates uncertainty for the courts and the parties[.]" == Notes ==