Hi. I am working on visualization of flow with thermal infrared camera. As it is known, water is not transparent for IR spectrum of light, so you can`t watch phenomena that are occuring "inside". You can only see things that are occuring on the interface of water and wall. I have been working with some fluids like acetone or dichloromethane, which are transparent only few millimeters. Now I am trying to find liquids that are transparent more than that, let`s say few cm. So, has anybody been working with such a fluid or does anybody know for a research/article, which has dealed with this things? Thx.