Wielgus had a diverse career in sports photography, entrepreneurship, and politics. After graduating from the School of Artistic Crafts in Warsaw in 1970, he began working with publications such as the "Sportowiec" magazine and later established his own magazine called Mecz (Match). His work in sports photography led him to cover the FIFA World Cup on four occasions.
Wielgus also founded the first Laboratory of Professional Photography in Poland. He published several photo albums and curated exhibitions showcasing his own works. In addition to his artistic pursuits, Wielgus was involved in football. From 1993 to 1996, he owned the football section of Polonia Warsaw and served as the chairman of its supervisory board.
Wielgus and Lesław Ćmikiewicz played roles in organizing Students' Sports Clubs and mini football tournaments for children associated with UKS. These efforts aimed to promote sports among young people. In 1995, Wielgus became vice-president of the Polish Football Association management board, contributing to the development of football in Poland.
Following the dissolution of the BBWR (Citizens' Movement for Democratic Action), Wielgus joined the Republican Party.