Winners of Photomarathon Sheffield will be chosen based on their creativity, humour and spontaneity.
The prize for the overall winner is a Leica camera.
Topic winners will receive £50 Harrison Cameras vouchers and a place at a Leica Akademie workshop.
Runners-up in each topic will win a place at a Leica Akademie workshop.
The best set of photos taken on a smartphone will win a Sony Cybershot WX2 digital compact camera.
The best set of photos taken by an under-16 entrant will win a Lomography Lomo'Instant Mini Black Edition camera.
Winners will be announced on Monday 17th September.