The subject for your photo can be anything as long as it is obviously empty. The images can be in colour or black and white.
Every photo submitted will be available for the crowd to rate once the submissions period has ended. You can see all the images uploaded to a contest, but will need to rate them to see how they’re ranked once the rating period begins.
Some contests on Photocrowd also have a judge. After the submission period closes the judge chooses their favourite images and writes some image reviews. The crowd and judge results will be announced on the same day.
For a more detailed explanation of how rating works, see our FAQs