RadialGradientExponential meaning of radius

I was following a tutorial and RadialGradientExponential was used, I thought I could replicate the part of the graph with a VectorToRadialValue equivalent. The result was the same apart for the dimension of the circle section, as can be seen in the images. So what is the correct interpretation of the Radius of RadialGradientExponential? It does not seem to be simply the distance from the center.