gay seznamka hodslavice Beamer paper size is smaller than usual paper size.
The “paper size” of a beamer presentation is fixed to 128mm times 96mm.

http://delab.it/?direktor=incontri-al-buio-chat&879=05 With this trick, the normal font can be shown nicely.
But be cautious setting the image size with absolute value.
or use

http://approches.com/?frenk=rencontre-celibataire-dieppe&68f=3c \includegraphics[width=0.6\textwidth]{graphics.pdf}

http://web.mit.edu/8.13/presentations/beameruserguide.pdf

Citation