You can insert the images of your choice with good resolution in this theme. The 1200×900 size images will be the best throughout the site.

Beside it, you can upload following image sizes as per layouts :

1. The recommended image size for full width is 1200*900 PX.
2. The recommended image size having sidebar is 800*600 PX.
3. The recommended image size for post listing is 780*600 PX.

Note: If you’ve switched the theme, don’t forget to regenerate all the thumbnails. Otherwise, images will be displayed in undesirable sizes. Use Regenerate Thumbnails, plugin to regenerate thumbnails.