Problem of stretched images.

Hello, I have a problem with the image on the front page, when I puts an image she caroussel and in the news puts itself everywhere at the same time, in the slider. Only the dimensions are not the same everywhere of the blow she finds itself stretched especially in the caroussel. I shall like knowing if we can choose an image as every thing. For example an image for the slider, an image for the caroussel and an image for the news which are different to avoid this problem of stretching. Thank you