How to correctly set functions with `\left(` and `\right)`?

Question

If one uses \left( and \right) to set functions an extra space is created between the function name and the brackets. How does one correctly set functions?

Here is an example:

\documentclass{article}

\begin{document}
  Compare \[f(\frac{1}{2})\] and \[f\left(\frac{1}{2}\right)\].
\end{document}

Edit

Here is a (probably too easy) solution by using a negative space:

f\!\left(\frac{1}{2}\right)

Answer 1

\mleft and \mright of package mleftright avoid the additional space. Also often a slightly smaller version can be set manually improving the output. In this case, I would reduce the size of the fraction.

\documentclass{article}
\usepackage{mleftright}

\begin{document}
  Compare: \[f(\frac{1}{2})\]
  \[f\left(\frac{1}{2}\right)\]
  \[f\mleft(\frac{1}{2}\mright)\]
  \[f\Bigl(\frac{1}{2}\Bigr)\]
  \[f\mleft(\tfrac{1}{2}\mright)\]
\end{document}