First, check to make sure the Finder Scope is lined up with the correct object. You can do this by reading the name listed on the Finder Scope and comparing it to the name of your desired object. If the object the Finder Scope is focused on is not the object you want, try moving it slightly and see if you can detect your object.
You can also check that the thumbnail that shows up on the Finder Scope matches the image you want to research. You may sometimes find that your Finder Scope is looking at an infrared image when you were trying to research the x-ray image, or something of that nature.