There was a range of ultra-low iso slidefilms for artificial Tungsten light from Kodak that delivers all kinds of color-nuances and shades. These films were quite durable and stable, so they were actually quite suitable for many kinds of weather conditions and photojournalists, that always had to be sure that they can deliver results whenever it's needed. One of my favourites in this row must be the Kodak Ektachrome 320ET - a true survivor.
When building my stock of films (my freezer door is full), I was looking for a fast slide colour film. I decided to try the Sensia 400, which Fuji claims that is fast as a 400 ISO yet it has the grain of a 100 ISO... is this true?