From 1957 to 1958 Markus was a picture editor for Helsingin Sanomat. Since 1959 Markus was a freelance journalist and photographer for various magazines. Markus made the film Vaivaisveistokset in 1970. Also, he carries out research on Finnish folk art, especially wood carvings.
Since 1978 Markus has been managing director of Oy Valokuvakirja-Photobook Ltd. publishing company and director of the Photobook Gallery in Helsinki.