I made an informal comparison between these two films, given that Ektar is poised as a replacement for slide films. The pictures were taken with my Mamiya C330, 105mm f/3.5 DS lens in Gaspésie. The sun was starting to set, so the light was a bit warm. I might have used a Skylight filter, but I'm not sure. Both photos are lab scans, and I slightly adjusted the curves to remove a colour cast on the Ektachrome. Here's the Ektachrome E100VS: And here's the Ektar 100: Here is a 100% detail from the Ektachrome: And one from the Ektar: Overall, I can't say that the Ektar is a straight replacement for E100VS, but it has significant advantages in terms of grain, resistance to colour casts, contrast, and printability. On the other hand, E100VS has a much more painterly look, and has a well-defined palette.