Background image hover transition not working in chrome - html

Question

CSS Transition is not working in chrome on image hover, please check the JSFiddle example
HTML
<div class="screenThum">
</div>
CSS
.screenThum .portfolio{
width:350px;
display:block;
height:100%;
background-size:100%;
background-repeat:no-repeat;
height:250px;
position:relative;
opacity:0.4;
-webkit-transition: all .8s ease-in-out;
-moz-transition: all .8s ease-in-out;
-ms-transition: all .8s ease-in-out;
-o-transition: all .8s ease-in-out;
transition: all .8s ease-in-out;
}
.screenThum .portfolio:hover{
opacity:0.9;
background-size:120%;
}
I have tried with previous SO answers but didn't worked with my code, not sure whats wrong?
thanks

Answer 1

If you are comfortable with it then you can use transform:scale
to get same effect. Edited: taking the reference of #Alexandre Beaudet
.screenThum{
overflow: hidden;
width: 350px;
height: 250px;
}
.screenThum .portfolio{
width:350px;
display:block;
height:100%;
background-size:100%;
background-repeat:no-repeat;
height:250px;
position:relative;
opacity:0.4;
-webkit-transition: all .8s ease-in-out;
-moz-transition: all .8s ease-in-out;
-ms-transition: all .8s ease-in-out;
-o-transition: all .8s ease-in-out;
transition: all .8s ease-in-out;}
.screenThum .portfolio:hover{
opacity:0.9;
-moz-transform: scale(1.2,1.2);
-webkit-transform: scale(1.2,1.2);
transform: scale(1.2,1.2);
}
<div class="screenThum"></div>

Answer 2

Try to set screenThump width & overflow: hidden. Then use the transform: scale(x) property. This way you will get the zoom effect and the image will not get out of the container width.
.screenThum {
overflow:hidden;
width: 350px;
}
.screenThum .portfolio{
width:350px;
display:block;
height:100%;
background-size:100%;
background-repeat:no-repeat;
height:250px;
position:relative;
opacity:0.4;
-webkit-transition: all .8s ease-in-out;
-moz-transition: all .8s ease-in-out;
-ms-transition: all .8s ease-in-out;
-o-transition: all .8s ease-in-out;
transition: all .8s ease-in-out;
}
.screenThum .portfolio:hover{
opacity:0.9;
transform: scale(3);
}