A number of Waldman's publications employ a combination of archival research and connoisseurship to identify and reconstruct the careers of previously anonymous artists of the Renaissance. In a long series of essays, they established the identities of such prolific painters as
Giovanni Larciani (formerly known as the Master of the Kress Landscapes),
Bartolomeo Ghetti (formerly known as the Master of the Copenhagen Charity),
Bernardo di Leonardo (formerly the Master of Memphis), Mariotto di Francesco Dolzemele (whom he hypothetically identified as the Master of Serumido), and others. Waldman is known as a scholar unafraid of controversial topics. In 2007 an international media coup resulted from the claim by Hungarian art historian Mária Prokopp and Zsuzsanna Wierdl art restorer that a fresco in the Archiepiscopal Castle of
Esztergom in
Hungary was the work of
Sandro Botticelli. The official endorsement of their discovery by Hungary's Minister of Culture in a much publicized press conference made debate difficult for by Hungarian academics and curators. Waldman published the first extended refutation of the Botticelli theory, which on the basis of historical and stylistic evidence he described as "abszurdus" (absurd). That negative judgement has been now reaffirmed by subsequent researchers in Hungary and abroad. In the spring of 2008 Waldman identified a painting of the
Annunciation in a provincial museum of Hungary, the
Móra Ferenc Múzeum in
Szeged, as the work of
Giorgio Vasari. The work had previously been catalogued by the museum as the work of
Agnolo Bronzino. A number of scholars doubted the Vasari attribution. The controversy received considerable public attention after Waldman, writing in the catalogue of an exhibition held at the Szépművészeti Múzeum in 2009, presented a preparatory drawing made by Vasari for the painting (now in the Pierpont Morgan Library, New York) and identified it on the basis of documents as part of the lost decorations for the Chapel of St. Michael in the
Torre Pia of the Vatican, which Vasari painted for
Pope Pius V in 1570-71. Waldman again made headlines in April 2009 when they publicly presented documentary evidence revealing that some time before June 1505
Leonardo da Vinci painted a portrait of his beloved uncle,
Francesco da Vinci. They argued that the red-chalk drawing in Turin—one of the most famous drawings in the history of art due to its frequent misidentification as a self-portrait—is likely to be a preparatory study for the lost painting of Leonardo's uncle. ==Personal life==