Is it permissible to marry the daughter of a man who works as a photographer to earn his livelihood, knowing that he takes both necessary and other types of photos? Is all of his earnings unlawful? And in this situation, is it permissible to visit the wife's family, eat their food, and accept their gifts?

There is no objection to you marrying the girl whose father works as a photographer. You should advise her father to limit his work to permissible matters. If he tells you that he engages only in permissible activities, then accept that from him. Otherwise, you may refrain from partaking of his food and gifts that are doubtful due to the suspicion of being unlawful, but without shunning him or ceasing to visit him. Rather, continue to advise him and assist him if you are able.