[Tex/LaTex] Make lens aperture in Tikz

Question

I want to make a lens aperture with different f numbers(sizes of the holes). I started with this code but it wont make it look like a complete aperture. Appreciate any help.

\documentclass[aspectratio=43]{beamer}
\usepackage{tikz}


\begin{document}

\begin{frame}{Aperture image}

\begin{tikzpicture}
\clip (0,0) circle(1);
\draw[thick] (0,0) circle(1);
\foreach \r in {0,40,...,360}
\filldraw[fill = black!80,draw = white,thick, rotate = \r] (-3,-1) rectangle (-0.5,1);
\end{tikzpicture}
\end{frame}
\end{document}

The current output is looking like this.

Answer 1

You could draw triangles instead of rectangles:

\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
  \clip (0,0) circle (1);
  \foreach \r in {0,40,...,320}
    \fill[black!80,rotate=\r] (-0.5,1) -- (-0.5,-0.13) --++ (130:1) -- cycle;
\end{tikzpicture}
\end{document}