Hola Juan
Photography is as free as the painting, in both cases have different techniques and styles and thus different techniques.
Painting and photography are practically the same, each with its advantages, but all can do either.
For example, a surrealist painting has many fantasy elements, in photography would have to make use of many wires to hold all the magic you want to put in photo or make use of publishing techniques and computer.
If we talk about portrait, painter use (most times) natural lighting and put in front of the subject, in the photograph is the same, speaking of studio photography lights and will subject the same way, etc.
I believe that photography is as free as the painting, one must recognize that each style is necessary to use tools. (Computer, photographic enlarger, negative or files) (brush, spatula, sponge, oil hard or soft, solid or wet technique, etc).
When I studied art at the art school I realized that every artistic representation can represent the same thing as another, the painting has to take advantages of photography and photography take advantages of painting, and to compete with these advantages should use tools.
Regards