How to get images to fill boxes in Big Grid Slide?

We are using the Big Grid Slide at the top of our website at http://www.bikerumor.com but the feature images are not filling the entire boxes, instead leaving gray space that looks terrible. How do we set it so that the images scale (proportionally) to fill the boxes? It’s OK if they get cropped, we just want the box filled with image rather than the image cropped to fit.

Thanks,
Tyler

Did you regenerate your thumbnails to make the proper size images? I think you have to do that, per the docs … but double check that.

It fills the space when the window is narrower, but when I pull my browser window wide, it gets to a point where the images stop filling the space. It’s almost like it’s made for smaller screens at the detriment of full desktop (laptop) viewing.