Do you still own it after selling 500px?

Don't belong. After 500px sells the picture, the copyright of the picture does not belong to you, but you still enjoy the right of signature. On a photo sharing and selling platform like 500px, when a photographer chooses to sell his own pictures, he will generally sign a copyright transfer agreement with the platform or the buyer. Once the picture is sold, the copyright will usually be transferred to the buyer, and the photographer will no longer have the right to use the copyright of the picture. However, the photographer still retains the right to sign the picture, that is, the right to indicate that he is the original author on the picture.