Question: Who wrote more books that became films, Tracy Chevalier or Roland Barthes?

Context articles: Mythologies (book)
A Lover's Discourse: Fragments
S/Z
Tracy Chevalier
Effect of reality
Incidents
Writer Sollers
Roland Barthes
Writing Degree Zero
Camera Lucida (book)

Mythologies is a 1957 book by Roland Barthes.
 It is a collection of essays taken from "Les Lettres nouvelles", examining the tendency of contemporary social value systems to create modern myths. Barthes also looks at the semiology of the process of myth creation, updating Ferdinand de Saussure's system of sign analysis by adding a second level where signs are elevated to the level of myth.
A Lover's Discourse: Fragments (French: "Fragments d’un discours amoureux" ) is a 1977 book by Roland Barthes.
 It contains a list of "fragments", some of which come from literature and some from his own philosophical thought, of a lover's point of view.
 Barthes calls them "figures"—gestures of the lover at work.
S/Z, published in 1970, is Roland Barthes's structural analysis of "Sarrasine", the short story by Honoré de Balzac.
 Barthes methodically moves through the text of the story, denoting where and how different codes of meaning function.
 Barthes's study has had a major impact on literary criticism and is historically located at the crossroads of structuralism and post-structuralism.
Tracy Chevalier FRSL (born October 19, 1962) is an American-British historical novelist.
 She has written eight novels.
 She is best known for her second novel, "Girl with a Pearl Earring", which was adapted as a 2003 film starring Scarlett Johansson and Colin Firth.
The effect of reality (French: "effet de réel" ) is a textual device identified by Roland Barthes the purpose of which was to establish literary texts as realistic.
 Barthes first suggested this concept in his 1968 essay "The Reality Effect," in which he argues that untheorized descriptive "residues" of the text produce effects of reality through their dissembling of the tripartite sign.
 In the absence of any signified, Barthes argues, the textual signifiers for "real" objects had for their actual signifieds only the concept of realism itself; further, Barthes suggested that the origins of this textual device came through the development of an "aesthetic finality of language" present in the use of the rhetorical device of ecphrasis in "Alexandrian neo-rhetoric of the second century" ("The Reality Effect" in Barthes 1989).
Incidents (French: "Incidents" ) is a 1987 collection of four essays by Roland Barthes.
 It was published posthumously by François Wahl, Roland Barthes's literary executor.
Writer Sollers (French: "Sollers écrivain") is a short book published in 1979 by the French literary critic Roland Barthes.
 In his discussion of the controversial French writer, Philippe Sollers, Barthes raises critical issues of central importance such as the nature of narrative, the theory of language, the problems of traditional realism and the relationship between literature and politics.
Roland Gérard Barthes ( ; ] ; 12 November 1915 – 26 March 1980) was a French literary theorist, philosopher, linguist, critic, and semiotician.
 Barthes' ideas explored a diverse range of fields and he influenced the development of schools of theory including structuralism, semiotics, social theory, design theory, anthropology and post-structuralism.
Writing Degree Zero (French: "Le degré zéro de l'écriture" ) is a book of literary criticism by Roland Barthes.
 First published in 1953, it was Barthes' first full-length book and was intended, as Barthes writes in the introduction, as "no more than an Introduction to what a History of Writing might be."
Camera Lucida (French: "La chambre claire" ) is a short book published in 1980 by the French literary theorist and philosopher Roland Barthes.
 It is simultaneously an inquiry into the nature and essence of photography and a eulogy to Barthes' late mother.
 The book investigates the effects of photography on the spectator (as distinct from the photographer, and also from the object photographed, which Barthes calls the "spectrum").