In this question, I have asked How I can plot the critical line of $\zeta(s)$ as the definition of $\zeta (s)$ is valid only for $s\geq 1$. One way to plot is to use $\eta(s)$ $$\eta (s)=(1-2^{1-s})\zeta(s)$$ I used this and the plot of $\zeta(0.5+it)$ $(-40\leq t\leq 40$) looks like this :
While the zeroes are at the right place, it's different from what is shown here
I wanted to know How come the same function looks different?
Edit: Thanks to all! The following plot uses $5000$ Terms of the $\eta$
