Crabtree joined Gainsborough Pictures. He worked on The First Offence with John Mills; Pot Luck with Tom Walls and Ralph Lynn; Everybody Dance with Cicely Courtneidge; and All In with Lynn for director Marcel Varnel. He went on to Good Morning, Boys with Will Hay; The Great Barrier with Richard Arlen, shot partly on location in Canada; Said O'Reilly to McNab with Will Mahoney and Will Fyffe; and Oh, Mr. Porter! with Hay. Crabtree shot Bank Holiday for director Carol Reed starring Margaret Lockwood. He did Convict 99 with Hay; Alf's Button Afloat with The Crazy Gang for Varney; Old Bones of the River and Hey! Hey! USA with Hay; The Frozen Limits with The Crazy Gang. Most of these films were directed by Marcel Varnel. So was Where's That Fire? with Hay; and Band Waggon with Arthur Askey. He did some photography work on Neutral Port. Crabtree shot For Freedom with Will Fyffe; Charley's Aunt with Askey; and Neutral Port with Fyffe. He did a short for director Anthony Asquith, Channel Incident and one for Herbert Mason, Mr. Proudfoot Shows a Light. After doing Gasbags with the Crazy Gang, Crabtree was used by Carol Reed on Kipps at Fox. For that company he also did Inspector Hornleigh Goes to It ; and Once a Crook, and another short for Asquith, Rush Hour. Back at Gainsborough Crabtree shot I Thank You with Askey. After doing South American George with George Formby at Columbia, he did Uncensored for Asquith at Gainbsorough. He did another with Formby at Columbia, Much Too Shy, then went back to Gainbsorough for King Arthur Was a Gentleman with Askey.
Gainsborough Melodramas
Crabtree was cinematographer on Gainsborough's The Man in Grey, a huge hit which started the Gainsborough melodrama cycle and made stars of James Mason, Margaret Lockwood, Phyllis Calvert and Stewart Granger. He shot a comedy with Lockwood, Dear Octopus, then did another melodrama, Fanny by Gaslight, directed by Asquith and starring Calvert, Granger and Mason, another huge success. Crabtree followed this with Waterloo Road starring Granger and John Mills, directed by Sidney Gilliat.
Director
Crabtree had filmed some of Gainsborough's biggest successes and the studio promoted him to director for Madonna of the Seven Moons with Calvert and Granger. Phyllis Calvert later recalled:
Arthur was a very good cinematographer, but there weren't enough directors, and so people who were scriptwriters or were behind the camera were suddenly made directors. It wasn't that Crabtree was an unsatisfactory director, just that we found ourselves very satisfactory – we did it ourselves. But the fact that he had been a lighting cameraman was wonderful for us, because he knew exactly how to photograph us.
The film was very popular at the box office. So too was Crabtree's second effort as director, They Were Sisters with Calvert and Mason, and his third, Caravan with Granger. Crabtree directed a thriller with Eric Portman and Greta Gynt, Dear Murderer. He followed this with The Calendar, with Gynt, and was one of the directors on Quartet.