"Photography" is the art, job or action of taking photos. What you need there is the noun "photograph". And, since you have a person there, you need to establish the possession relation by adding "`s". So it would be:
When you are talking about more than one person you add the apostrophe at the end of the word, without adding an "s". So it would be:
Can you notice the differnce? Be careful and don`t confuse with nouns such as children. It is not "the childrens`rights" neither "the children`rights". It is "the children`s rights".
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