From the second edition (1989):
(pɔːˈnɒgrəfɪ) [f. as prec. + -y. So F. pornographie.]

1. (See quot.)

1857 Dunglison Med. Dict., Pornography, a description of prostitutes or of prostitution, as a matter of public hygiene. 1858 in Mayne Expos. Lex. 1895 in Syd. Soc. Lex.

2. a. Description of the life, manners, etc., of prostitutes and their patrons; hence, the expression or suggestion of obscene or unchaste subjects in literature or art; pornographic literature or art. Also qualified by hard or soft, with reference to hard core (b) s.v. hard a. 23b, soft core s.v. soft a. 29, to denote pornography of a more, or less, obscene kind. Also transf.

1864 Webster, Pornography, licentious painting employed to decorate the walls of rooms sacred to bacchanalian orgies, examples of which exist in Pompeii. 1882 Daily Tel. No. 8313. 5/4 Pictorial and glyptic ‘pornography’‥grew, flourished, declined, and fell with the Second Empire. 1896 Mackail Lat. Lit. 18 The Casina and the Truculentus [of Plautus] are studies in pornography which only the unflagging animal spirits of the poet can redeem from being disgusting. 1930 W. S. Maugham Gent. in Parlour xii. 64 Pornography rather than brevity is the soul of wit. 1968 Sat. Rev. (U.S.) 19 Oct. 23 In recent years the movies and television have developed a pornography of violence far more demoralizing than the pornography of sex, which still seizes the primary attention of the guardians of civic virtue. 1972 Times Lit. Suppl. 7 Jan. 12/2 Of course pornography should never be treated as if only its sexual aspects mattered—that is, as if no other kind of stimulus offered by the written word could be as socially or ethically significant. 1976 Time (Canada ed.) 5 Apr. 36/1 What pornography is can endlessly be debated. One rough definition: explicit books, films and other materials (including, by extension, performances) designed chiefly for sexual arousal. 1977 Broadcast 30 May 3/3 [Italian] ‘pirate’ TV stations which flourish on‥‘soft pornography’. 1977 Lancet 11 June 1241/2 A distinction could be drawn between erotic art (or soft pornography)‥and hard pornography, which by connecting sex with violence, hatred, pain, and humiliation, stimulated gratification of sexual desire in deviant ways.

b. In transf. and extended uses.

1968 [see above]. 1977 Listener 17 Nov. 655/4 Turgid moralising‥is the real English vice, the pornography of our day.

So porˈnographist, a writer on pornography.

1893 Nation (N.Y.) 3 Aug. 79/2 The ‘grossness of the naturalists and the subtleties of the pornographists’, to use the words of M. Lavisse, cannot have any other result.