Feature Request: Way to keep slider images uniform

I am not sure if you have a feature request area, but I wanted to mention that this is my main problem when manipulating the theme. Whenever I write a post, I have to adjust each feature image to a uniform setting through other software, and it keeps me from being able to update my slider with new posts that I want to feature there.

I often have photos that do not fit the ratio needed to display correctly. Does anyone else see this as an issue? If there is a quick fix that goes beyond resizing every single feature image, I would love to know!