[orbit-slider category="my_category" numberposts="3"] The slider is responsive, therefore will stretch to the surrounding div. The featured thumbnail is set to a width of 540px and a height of 450px. It is also set to hard-crop. If your wish to have custom dimensions…
1. In your functions.php add:
Note: true parameter forces hard crop of image.
2.Then in the slider options ‘Advanced Settings’ select ‘Custom Size’.