Results of using an RGB-D camera (Kinect sensor) and a stereo camera, separately, in order to determine the 3D real position of characteristic points of a predetermined object in a scene are presented. KAZE algorithm was used to make the recognition, that algorithm exploits the nonlinear scale space through nonlinear diffusion filtering; 3D coordinates of the centroid of a predetermined object were calculated employing the camera calibration information and the depth parameter provided by a Kinect sensor and a stereo camera. Other comparisons have been made using different types of cameras similar to those used in this work, however, a conclusion of the best performance depends on the specific application, for example, it has been shown that for 3D surface reconstruction, the Intel RealSense D415 camera has higher precision than the Kinect. Experimental results of this work show it is possible to get the required coordinates with both cameras in order to locate a robot, although a balance in the distance where the sensor is placed must be guaranteed: no fewer than 0.8 m from the object to guarantee the real depth information, it is due to Kinect operating range; 0.5 m to stereo camera, but it must not be 1 m away to have a suitable rate of object recognition, however, without loss of generality it can be concluded that the Kinect presents greater precision in the distance measurements with respect to the stereo camera.