What makes a nude photograph taken for free art, whilst a nude for profit is smut? I submit that it is the quality of the work which is at issue, and not the means by which the artist pays his bills.
There is a subtle difference between sexuality and sexism, and those who object to one often think they are objecting to the other. A woman who enjoys her body and wishes to show it off is appreciated by men who wish to admire her beauty from afar, in their bathroom. I do not believe either to be wrong in their desire for happiness, nor in their methods of finding it. Although I acknowledge that any such recreation should not get out of hand, as it were.
One famous actress said that she posed for playboy because she felt too inhibited and unsure of her body. She wanted to feel better about herself, and now her husband has difficulty getting her to wear clothes at all. Another said that it had been a life-long dream of hers to pose for playboy, that was how she knew she'd "made it."
Throughout the suffrage movement, one of the biggest sources of opposition has come from conservative women, and the deeply ironic shift today is for these women to call themselves feminist, while comdemning pornography as exploitive and repressive towards women. Yes, I am talking to you.
Many muslim women have expressed the sentiment that they feel freed by their veil, that wearing it makes them feel safe and able to be themselves more fully. I condone their sentiment whole-heartedly, save this; your freedom to do something is not license to force your sentiments upon everyone else.
A woman who may wear a veil to express her religion is freer than a woman bereft of hers. Yet a woman who may not safely go outdoors without that veil is in no way free at all. She has been given no choice.
A woman who is pressured into nude photography by need for money or love is imprisoned by her need. She is exploited and abused. A woman who chooses to pose for photos out of her own joy in her body and the joy it brings others: she is freed by that choice, and it is no-one's right to take that from her.