# \Phi looks bad in Beamer

I'm making a beamer presentation. If I write $\Phi$ it kind of looks bad in beamer, like shown below. I want a better looking $\Phi$ like in article.

• Just sayin'...the \Phi in beamer is consistent with a sans serif font. The default article shape differs in that it has serifs on the center strut, consistent with the rest of the default computer modern math font found in article. – Steven B. Segletes Aug 26 at 15:41
• Does this answer your question? tex.stackexchange.com/questions/34265/… – Markus G. Aug 26 at 15:48
• I would also add that, in general, sans serif fonts are easier to read at longer distances, such as one finds the situation during screen presentations. This would explain why beamer (a screen presentation documentclass) defaults to sans serif alphabets. – Steven B. Segletes Aug 26 at 15:58
• Indeed, it looks better on the screen – yarchik Aug 27 at 8:26
• Accordingly, in the modern day of making slideshows for Zoom presentations which the audience will watch on their own computer screens, there is no reason to use a sans serif font (and I recommend switching to serif at least for math mode). – Misha Lavrov Aug 27 at 17:18

Rather that import a different \Phi, which will in general not be compatible in style with the pre-existing font, I instead here choose to add small serifs to the existing rendering of \Phi, calling it \altPhi. I have made it work in all math styles.

\documentclass{beamer}
\usepackage{stackengine,scalerel}
\newcommand\altPhi{\ThisStyle{\ensurestackMath{
\stackengine{-.6\LMpt}{%
\stackengine{-.7\LMpt}{\SavedStyle\Phi}{\rule{.5\LMex}{.7\LMpt}\kern.01ex}
{U}{c}{F}{F}{S}}%
{\rule{.5\LMex}{.7\LMpt}\kern.01ex}{O}{c}{F}{F}{S}}}%
}
\begin{document}
\begin{frame}
$\Phi \altPhi$
$\scriptstyle\Phi \altPhi$
$\scriptscriptstyle\Phi \altPhi$
\end{frame}
\end{document}


With the professionalfonts class option, you can load the font of your choice. Your options include:

• Any OpenType font with unicode-math. You can even add the \Phi symbol from another font with \setmathfont[range=\mupPhi]{SomeFont.otf} (If you select math-style=ISO, which gives you slanted uppercase Greek letters, you would override \mitPhi instead of \mupPhi.)
• Any OML-encoded font with isomath
• Any LGR-encoded font with mathastext
• Any math font package
• Any OT1-encoded font, with \DeclareMathAlphabet. (These have uppercase, but not lowercase, Greek letters.)

If you can choose which compiler and packages to use, I would recommend that you use unicode-math with a sans-serif font such as Fira Math, and compile with LuaLaTeX.

You can switch using mathastext package with the options italic and symbolgreek: but the Greek symbol are in upright mode.

\documentclass[12pt]{beamer}

\usepackage[italic,symbolgreek]{mathastext}

\begin{document}
\begin{frame}
$\Phi_n(x)=\prod_{\zeta \text{ primitive }}{(x-\zeta)}$
\end{frame}
\end{document}