I suspect that you're looking at the right sorts of websites, but the reason you're not seeing any jobs advertised is that there aren't any such jobs. Or at least there aren't any that are filled by advertising on the open market.
A few years ago I wanted to recruit a customer service person. I put a tiny little advert in the local newspaper and I received 149 applications. Sifting through them was a *huge* amount of work, but as an employer you have to do it properly because you can't afford to run the risk of an unsuccessful applicant claiming that you discriminated against them. (As it was, my short list was 90% white despite the pool of applicants being much more diverse, and I agonised over that and thoroughly reviewed my selection criteria before concluding that I really had selected the "N" best candidates.)
These days the rise of websites such as Reed and Monster makes it far easier for people to apply for jobs for which they're really not suitable, which creates more work for the employer. Plus, I expect that reviewing the credentials for a photographer is much harder than for, say, an office administrator. So it wouldn't surprise me at all if employers who have such vacancies do everything they legally can to fill them without going out to the open market via jobs websites.
This is all speculation of course. Take it with a suitable punch of salt.