Ergo loupes are excellent, and not just those from Lumadent. I purchased mine from Pentax, and they are outstanding. Initially, I was using a magnification of 3.5x, but I switched to 3.0x. Honestly, you don't need to see every detail of the tooth. Anything between 2.5x and 3.5x will suffice. I also have a regular pair of loupes from Orascoptic (eyezoom x3-5) where you can change the magnification, but I rarely go over 3x, which is its minimum magnification.