Are you trying to make it responsive? If you are then I would just recommend the following:

.tales {
  width: 100%;
}
.carousel-inner{
  width:100%;
  max-height: 200px !important;
}

However, the best way to handle this responsively would be thru the use of media queries like such:

/* Smaller than standard 960 (devices and browsers) */
@media only screen and (max-width: 959px) {}

/* Tablet Portrait size to standard 960 (devices and browsers) */
@media only screen and (min-width: 768px) and (max-width: 959px) {}

/* All Mobile Sizes (devices and browser) */
@media only screen and (max-width: 767px) {}

/* Mobile Landscape Size to Tablet Portrait (devices and browsers) */
@media only screen and (min-width: 480px) and (max-width: 767px) {}

/* Mobile Portrait Size to Mobile Landscape Size (devices and browsers) */
@media only screen and (max-width: 479px) {}

If you use bootstrap 4 Alpha and you have an error with the height of the images in chrome, I have a solution: The documentation of bootstrap 4 says this:

<div id="carouselExampleSlidesOnly" class="carousel slide" data-ride="carousel">
  <div class="carousel-inner" role="listbox">
    <div class="carousel-item active">
      <img class="d-block img-fluid" src="..." alt="First slide">
    </div>
    <div class="carousel-item">
      <img class="d-block img-fluid" src="..." alt="Second slide">
    </div>
    <div class="carousel-item">
      <img class="d-block img-fluid" src="..." alt="Third slide">
    </div>
  </div>
</div>

Solution:

The solution is to put "div" around the image, with the class ".container", like this:

<div class="carousel-item active">
  <div class="container">
    <img src="images/proyecto_0.png" alt="First slide" class="d-block img-fluid">
  </div>
</div>

I recommend the following for Bootstrap 3

.carousel-inner > .item > img,
.carousel-inner > .item > a > img {
  min-height: 500px;    /* Set slide height here */

}

I know this is an older post but Bootstrap is still alive and kicking!

Slightly different to @Eduardo's post, I had to modify:

#myCarousel.carousel.slide {
    width: 100%; 
    max-width: 400px; !important
}

When I only modified .carousel-inner {}, the actual image was fixed size but the left/right controls were displaying incorrectly off to the side of the div.