Answer:
   
   A camera may not be used on Shabbat or holidays. Creating the
   photographic image would raise problems with two of the 39 categories
   of melechah prohibited on Shabbat: coloring/dying, and
   writing/drawing. Additionally, most cameras use electronics, which
   heat up filaments and a flashbulb (cooking or kindling), motors spark
   internally (kindling), closing a circuit is completing it (a "final
   hammer blow", as the concept is called in the Talmud). Lastly, posing
   for the picture intentionally raises the issues of coloring or
   drawing. So, if the picture is for your benefit you can't
   intentionally walk into the field in front of the lens.
   
   Anything a Jew can't do for himself, he can't ask a non-Jew to do for
   him; however, he can enjoy it if a non-Jew did it for him without his
   asking. There are exceptions, such as for communal need (such as the
   synagogue janitor), or to prevent massive loss. How does this apply to
   taking a picture? Consider a security camera. One doesn't gain by
   having your own picture taken in such a case, and such pictures serve
   to prevent massive loss. After all, the camera doesn't protect you
   from yourself. Thus, walking by an apartment building's security
   camera is permissable (in nearly all contemporary Orthoodox opinions).