By 1916, Sydney had got into films, probably through contacts he had from his earlier theatrical days. There were a number of his friends living locally who were in the film business already.

The first film in which Sydney is known to have appeared was called The Girl Who Loves A Soldier which was a war film made at Isleworth studios in 1916. The star was the male impersonator Vesta Tilley and the film was directed by Alexander Butler and produced by G B Samuelson who owned the studios. The storyline was set during the First World War when a nurse (Vesta Tilley) disguised herself as a man and carried important military dispatches her wounded fiancé (Sydney Folker). The book Britain's Forgotten Film Factory by Ed Harris has a lot of detail about the making of this film, but does not mention Sydney, even though he was the co-star. Vesta Tilley was also working in the music halls at that time to recruit soldiers and one of her songs was called Jolly good luck to the girl who loves a soldier. During a visit to the British Film Industry in London, Sidney's daughter Doady met by chance the biographer of Samuelson, who had been commissioned by Samuelson's son. Sydney had worked under Samuelson at studios at Isleworth and Doady had recollections of watching her father.

The Samuelson's film company had a holiday camp at Cliftonville in Kent where employees would take their holidays. There are many photos of this period amongst Sydney's keepsakes.

A article in The Sheilds Daily Gazette records an event when Sidney, as a passenger in an aeroplane, was obliged to take the controls and land it. It is not clear if this was fact or fiction as no other references have been found.

A magazine article in 1922 noted that Sydney had been working with the London Film Company then with Alliance as studio manager and technical director. The St. Margaret's studio was owned by the London Film company but they sold to Alliance Films in 1920. Sidney's daughter Doady recalls that near to the studio was a furniture warehouse from which the production team would rent furniture for their sets.

The next references found are for two films in which Sydney appeared in 1920, both made by Fred Paul British Standard Film Productions. The first was The English Rose in which Sydney played the part of Harry O'Malley who sells his home and falls in love with the buyer's daughter. Filming was completed in March. The second of the series in which Sydney also appeared was Uncle Dick's Darling, the story of a caravanner who dreams that his adopted daughter would marry an MP, rather than the pilot (Sydney Folker), that she loves.

Sydney was responsible for the sets for the International Artists Film Company Limited presentation of Nighthawk. The date that the film was made is not known.

Later in 1921, Sydney played the part of Bill Saunders in Vi of Smith's Alley directed by Walter West and produced by Broadwest Films. That year he also played Jim West in The Corner Man which was directed by Norwegian born Einar Bruun and produced by Harma-Associated Exhibitors. In August 1921, the external scenes were filmed at Cockington Mill and a few photographs taken there at the time have survived. The final scenes of the film were shot at the end of October. Sydney received a letter from a fan regarding his playing in this film.

According to a report in Kinematograph Weekly on 23 February 1922, Sydney had signed up with Quality Plays who had only been formed in December the previous year with their offices at 22 Denman Street, London, W 1. They were about to produce a series of four 'one reelers' in the former Screenplays studios in Clapham. They were silent films and the audience would have a program which described the story. Sydney was working as an actor for Quality Films but was also Studio Manager. Kinematograph Weekly of 27 July 1922 describes the first four films as extraordinarily good and brim full with appeal to all emotions. The stories were adapted from popular magazines such as Truth and the fiction magazine Pan. The films, directed by George A Cooper, were distributed fortnightly by Walturdaw Company Limited. The first film of the series was called The White Rat being released in November 1922 and for which Sydney was noted in "Pictures and Picturegoer magazine of 1 January 1923 as the popular juvenile lead (at age 34!), and described him as an accomplished art director in addition to being an accomplished artiste. Elsewhere he was stated as being a worthy successor to Sidney Drew. The other three titles were A Question of Principle, Fallen Leaves and The Thief. Two more titles were added to this series, Geraldine's First Year and Big Strong Man. Filming was completed in August 1922.

Kinematograph Weekly of 7 September 1922 announced that Quality Films were embarking on a new series of films, these to be light comedies about a young married couple called The Cunninghams. Sydney and Joan MacLean were to play the leading roles. Sydney would also have continued as Studio Manager. The first in the series was The Letters followed by The Cunningham's Economise. Next was Poetic Licence in which Sydney did not appear but he was in Keeping Man Interested for which work started in week commencing 25 October 1922. He was not in Pearl upon Pearl but was in the cast of Her Dancing Partner. The two series of films were listed in a brochure issued by Quality Plays.

Film companies in these early days were generally small and plentiful but short-lived. This applied to Quality Film Plays, despite the acclaimed ability of their producer, George A Cooper. Correspondence in the middle of 1923 hints at looming problems at Quality Film Plays. The Kinematograph Weekly edition of 23 August 1923 reports that George Cooper had moved to work for Gaumont. However, it was more than that as Gaumont also absorbed Quality Plays, retaining the name and releasing new films under that name. It is not known if Sidney or other staff were retained by Gaumont, but the article also notes that filming is due to start in Lime Grove Studios in Shepherd's Bush, and it was recalled by the family that Sydney did work in those studios at some time.

The next film in which Sydney is known to have appeared was Becket which was produced by Stoll Films at their studios in Cricklewood. Work started in 1923 and the film was released on 4 February 1924. There are some references at the National Film Archive relating to Sydney. Doady and her son Malcolm visited the archive in 1979 when it was located in the West End of London and viewed the piece of film they have of Becket. Unfortunately, that the famous scene of the killing of Thomas A'Beckett at the altar of Canterbury cathedral has not survived. At that visit, Doady donated some programmes of films in which Vesta Tilley had appeared also a set of photographs which had belonged to Sydney and which showed some of the stars, sets and stage hands of the films in which he had participated. The originals were kept by the Archive but they made copies of the photos and these are with the other keepsakes of Sydney in the possession of his descendants.

Sydney made another film with Stoll which started with the title 'Pools of the Past' but was released in 1924 as The Notorious Mrs Carrick. Amongst the many keepsakes handed down through the family is a copy of the original script. This is to be donated to the British Film Institute archive.

On 18 March 1924, Sydney appeared on stage with actress Marjorie Benson at The New Royalty Kinema on Brixton Hill in Brixton, London. This was in connection of daily appearances of film celebreties during All British Film Week. There are some references to Sydney appearing in 1925 in a film called The End of the World but little detail has been found.

The industry went into decline and Sydney was out of work for some time. It is believed that he was offered work if he agreed to move to the USA to take part in the early days of the talkies, but as his wife Vera was not happy at the prospect so he did not accept. Her secret reasons for declining are covered in her biography. He considered, at one point, emigrating to Australia to the point that they were ready to go but, for the same reasons, they never did.

A picture of Sydney appears in a set of cigarette cards issued by British American Tobacco in 1928 which comprises an alphabetic set of film stars. He jokingly used to tell his friends that the only reason that he was on these was that there was no-one else with a name that began with the letter F.