Just found a very delicate solution here: http://www.paulund.co.uk/absolute-center-images-with-css, using transform: translate() function
So my final example looks like this - http://codepen.io/anon/pen/EDgiz:
img{
position: absolute;
max-width: 100%;
max-height: 100%;
left: 50%;
top: 50%;
transform: translate(-50%, -50%);
-webkit-transform: translate(-50%, -50%);
}
Works Awesome for me