One chap who keeps cropping up in my research is (John) Gordon Lewis, a press photographer/cameraman.
From Antrim, he enlisted in the British Army on the 14th September 1914, becoming number 18094, Private, Royal Irish Rifles. 101 days later, 23rd December 1914, he was discharged as not likely to make an efficient soldier.
He moved to Dublin and joined a film company run by Norman Whitten. Whitten had filmed the funeral of the victims of the Bachelor's Walk Massacre in 1914 and the funeral of Donovan O'Rossa in 1915. Lewis appears to have done well and later captured much on film whilst also appearing in shots himself :
Lewis caught the death of Sean Treacy on camera, a work that is often confused with scenes from a fictional film from 1926 called Irish Destiny.
Whitten and Lewis worked on an early Irish film post war re The Days of St Patrick.
Whitten was to return to England while Lewis became a cameraman for British Pathe news.
The work of both these men can be seen in Mise Eire and Saoirse.