Reply To: Portfolio lightbox doesn't work with Optimal v1.3

Are you referring to the thumbnails that show up in your blog page? If so, that can be adjusted from your Genesis Theme Settings page. You can add more sizes in your functions file (just like the portfolio size that is there now) and then they will show up in your Genesis Theme Settings under Content Archives.

If you’re talking about the images that you add in a post, then that isn’t controlled by the theme, you would use WordPress’ image settings to control how they are displayed.

Anytime you change your thumbnail size anywhere in the theme, make sure and use the Regenerate Thumbnails plugin to automatically adjust all of your thumbnails to the size you have selected.