Are prayers performed without ritual bathing (ghusl al-janabah) due to ignorance of its obligation required to be repeated, and is photographing children and natural landscapes forbidden?

If you are certain that what was discharged from you after the fantasies was semen, which necessitates ghusl (definition) (ritual bath), then it is more cautious to make up the prayers you performed, in order to avoid dispute and clear your conscience. If you are not certain, then nothing is required of you. As for photographs, if they are of inanimate objects, they are permissible. If they are of living beings, there is a difference of opinion regarding them. The more pious approach is to avoid what is not necessitated by need, and anything that includes a forbidden element, such as nudity, is absolutely prohibited.