User blog comment:Lothorian Foryx/Switch Infoboxes/@comment-25345260-20130810154724/@comment-4536066-20130810165121

You really shouldn't have to use full-sizes OR thumbnails when it comes to infoboxes. Simply enter the name of the image (for example, "File:NatRenderra.png") and the infobox knows what to do with it. You don't need any further code, brackets, or specifications.