@donsoarese I agree, that anisotropy doesn’t make sense on an iris, but that’s the freedom you have as an artist.
Just watched this part and he doesn’t explain why he uses it either; he just likes the effect 😉
But now I see why he used the Min and Max of the Mapping Node and the same thing can be done now in the Image Texture Node:
This seems a bit easier than my first suggestiion, at least in cases like this. In general, when using other values for Min and Max, you’ll need to use the method with the Clamp Nodes…(there are other ways, but they get more complicated…)