Believe it or not, I have been able to start a fire indoors with a 1.5" dia magnifying glass and a lamp 2' away. (Using one lens of a triplex magnifier set).

It helped that the TinderQuick was already charred, ordinary TinderQuick would not do this. It took me by surprise as I was just goofing around one day. After seeing this, I charred a few more pieces and put them in my fire kit - anything that worked that quickly deserves a corner of my EDC survival kit.