How to disable static height cropping of the posts featured images
By default the theme crops the blog posts featured images to the same height:
If you would like to adjust this height or make the cropped images preserve their original ratios, you can adjust this for the corresponding blog layout in the Theme Options -> Media Settings -> Image Size -> Blog Images section.
If you would like to disable the static height cropping, just leave the height option for the corresponding post layout empty, for example for the three-column layout just leave the “Three-column layout image height” field empty: