What magnification level?????
After experimenting with a dental microscope before I purchased my loupes and trying both 2.5x and 3.5x settings I recommend 2.5x. Several 2nd years at Penn purchased 3.5x and now they regret it as the higher magnification narrows the depth of field and decreases angle of view – for general procedures you don’t need the increased magnification that 3.5x provides and I have no problem visualizing my preps with the 2.5x.