Slider

Hi guys.

I have a “problem” with my site.

I use the slider in hompepage, and I wanted to use as images the featured-images I have in each post. I don’t want they fill up all the entire slider box

So, the image I see now, are not the thumbnail, but scraps of the them.
I have already set the image-size in function.php, and I regenerated the thumbnails, but there is no way to show these thumbnails on the slider.

Any help?

Thanks