Some legalese (sic) for you to consider :
The general rule about first ownership of copyright is that the author is the first owner.
If you create a copyright work, you become the 'author' so in the case of any photographs you take you are the first owner. However, an example where this may not be the case is if it was you who pressed the camera button and someone else who decided things like the camera angle, exposure and so on.
This general rule about first ownership of copyright resting with the 'author' is, however, overridden in the case of photographs which are made by an employee in the course of employment; in this case, the employer is the first owner of copyright subject to any agreement to the contrary.
Hope this helps.
TAC