Boostrap responsitive image is deform in carousel mode - image

Question

I'm newbee in Boostrap and I try since 2 days to manage Boostrap carouseul mode.
My images in slide are Disproportionate when I resize navigator ! I was unable to find solution. I try many solution in CSS but I naver finnd solution.
I use default CSS parameter, present in carousel mode. I try carousel mode from w3schools (image are not corrupt when we resize navigator).
My CSS
/* Carousel base class */
.carousel {
height: 500px;
margin-bottom: 60px;
}
/* Since positioning the image, we need to help out the caption */
.carousel-caption {
z-index: 10;
}
/* Declare heights because of positioning of img element */
.carousel .item {
height: 500px;
background-color: #777;
}
.carousel-inner > .item > img {
position: absolute;
top: 0;
left: 0;
min-width: 100%;
height: 500px;
margin: auto;
}
My HTML
<!-- Carousel
================================================== -->
<div id="myCarousel" class="carousel slide" data-ride="carousel">
<!-- Indicators -->
<ol class="carousel-indicators">
<li data-target="#myCarousel" data-slide-to="0" class="active"></li>
<li data-target="#myCarousel" data-slide-to="1"></li>
<li data-target="#myCarousel" data-slide-to="2"></li>
</ol>
<div class="carousel-inner" role="listbox">
<div class="item active">
<img class="first-slide" src="media/image1.jpg" alt="">
<div class="container">
<div class="carousel-caption">
<h1>Secucampus.com</h1>
<p class="trans"> bla bla</p>
<p><a class="btn btn-lg btn-primary" href="#" role="button">Plus d'informations</a></p>
</div>
</div>
</div>
<div class="item">
<img class="second-slide" src="media/image2.jpg" alt="">
<div class="container">
<div class="carousel-caption">
<h1>Secucampus.com</h1>
<p class="trans">bla bla</p>
<p><a class="btn btn-lg btn-primary" href="#" role="button">Contactez nous</a></p>
</div>
</div>
</div>
<div class="item">
<img class="third-slide" src="media/image3.jpg" alt="">
<div class="container">
<div class="carousel-caption" style="text-align:left">
<h1>bla </h1>
<p></p>
<p><a class="btn btn-lg btn-primary" href="#" role="button">Contenu des cours</a></p>
</div>
</div>
</div>
</div>
<a class="left carousel-control" href="#myCarousel" role="button" data-slide="prev">
<span class="glyphicon glyphicon-chevron-left" aria-hidden="true"></span>
<span class="sr-only">Previous</span>
</a>
<a class="right carousel-control" href="#myCarousel" role="button" data-slide="next">
<span class="glyphicon glyphicon-chevron-right" aria-hidden="true"></span>
<span class="sr-only">Next</span>
</a>
</div><!-- /.carousel -->
The result when I resize image to Smarphone mode :
Thank for your help
Regard
Edit : Banzay :
I try to remove it and the result decrease image in hignht when I reduce the width of the navigateur.