Tungsten slide film may be temperamental, but once you get a feel for it, you can achieve some great x-pro results, often with purple color shifts!
Tungsten film is a professional slide film traditionally meant to be shot indoors, under—you guessed it—tungsten lights (as opposed to fluorescent light, natural light, etc). However, when cross-processed this film can yield some crazy purple and blue color shifts. I have not developed tungsten film in E6 chemicals—or those for regular slide film development, because I doubt that it would yield the color shifts.
I found that when using the tungsten film outdoors, in the daylight, the special effects were the least pronounced. Shooting on an overcast day brought out more of the character of the film. However, the best way to get that great, saturated color is to shoot indoors with a flash (and, it does not have to be under tungsten lighting for our x-pro purposes). You’ll get an even greater effect if you use the Lomography Color Splash Flash with a purple, blue, or magenta gel.
If you are shooting tungsten film, I highly recommend using a camera where you can manually adjust the ISO settings. Most tungsten films are rated at an ISO of 64. Most unfortunately, Lomography has discontinued their tungsten slide film, but Fujifilm makes a film that is quite similar, called T64. I have found that in most circumstances, the film performs best when the camera is set at ISO 100—so that the film is just a bit underexposed. Often, however, I will take several exposures, each at a slightly different ISO. I’ll usually set the ISO to 64, 100,150, or even 200. This ensures that out of the several different exposures of the same subject, at least one is likely to come out satisfactorily.
I should note that I have wasted some tungsten film in trial and error, but the exposures that did develop well are some of my favorite analogue pictures that I have ever taken. I love the purple color shifts that result from cross-processing. Give the film a try and let me know how you like it!