That need to be processed in the photos? Sometimes you need to lighten or darken the desired image area.
Unsuccessful exposure shooting object.

Photography Services. Price is per hour.

Image composed of several photographs or parts thereof, united by a common composition (easier to say, the general idea).

By itself, montage, may be:

and just replace the background,

and replacement of the color of clothes,

and substitution of the human face,

and installation of the objects, or people with several pictures.

Price is for 1 hour.