diff --git a/CmS_Zschertnitz.tex b/CmS_Zschertnitz.tex
index 358f175..ae3e537 100644
--- a/CmS_Zschertnitz.tex
+++ b/CmS_Zschertnitz.tex
@@ -11,7 +11,7 @@
 \usepackage[shadow,colorinlistoftodos]{todonotes}
 \setbeamertemplate{footline}[frame number]
 
-\newcommand{\cc}[1]{\includegraphics[height=4mm]{img/#1.png}}
+\newcommand{\cc}[1]{\includegraphics[height=4mm,keepaspectratio]{img/#1.png}}
 \usepackage{ifthen}
 \newcommand{\license}[2][]{\\#2\ifthenelse{\equal{#1}{}}{}{\\\scriptsize\url{#1}}}
 \usepackage{textcomp}
@@ -65,7 +65,7 @@
 \ \newline
 \begin{figure}
 	\centering
-	\includegraphics[width=5cm,height=7cm]{schneeschrauber.jpg}
+	\includegraphics[height=7cm,keepaspectratio]{img/schneeschrauber.jpg}
 	\label{}
 \end{figure}
 
@@ -74,7 +74,7 @@
 
 \begin{figure}
 	\centering
-	\includegraphics[width=5cm,height=5cm]{pentabug.jpg}
+	\includegraphics[height=5cm,keepaspectratio]{img/pentabug.jpg}
 	\label{}
 \end{figure}
 \newpage
@@ -86,7 +86,7 @@
 
 \begin{figure}
 	\centering
-	\includegraphics[width=2.5cm,height=2.5cm]{Chaosknoten.jpg}
+	\includegraphics[height=2.5cm,keepaspectratio]{img/Chaosknoten.jpg}
 	\label{ }
 \end{figure}
 
@@ -107,24 +107,24 @@
 
 \begin{figure}
 \flushleft
-\includegraphics[width=1cm,height=0.5cm]{1.png} Erfa in Dresden http://c3d2.de
+\includegraphics[height=1cm,keepaspectratio]{img/1.png} Erfa in Dresden http://c3d2.de
 \end{figure}
 
 \begin{figure}
 	\flushleft
-	\includegraphics[width=1cm,height=1cm]{pentacast.png} Podcast
+	\includegraphics[height=1cm,keepaspectratio]{img/pentacast.png} Podcast
 	\label{ }
 \end{figure}
 
 \begin{figure}
 	\flushleft
-	\includegraphics[width=1cm,height=1cm]{pentaradio.png} Radio
+	\includegraphics[height=1cm,keepaspectratio]{img/pentaradio.png} Radio
 	\label{ }
 \end{figure}
 
 \begin{figure}
 	\flushleft
-	\includegraphics[width=1cm,height=1cm]{datenspuren19.png} Konferenz http://datenspuren.de
+	\includegraphics[height=1cm,keepaspectratio]{img/datenspuren19.png} Konferenz http://datenspuren.de
 	\label{ }
 \end{figure}
 
@@ -161,7 +161,7 @@ Quelle: https://www.spiegel.de/netzwelt/netzpolitik/horst-seehofer-will-messenge
 
 \begin{figure}
 	\centering
-	\includegraphics[width=10cm,height=6cm]{haveibeenpwned.png}
+	\includegraphics[height=6cm,keepaspectratio]{img/haveibeenpwned.png}
 	\label{ }
 \end{figure}
 
@@ -174,7 +174,7 @@ Quelle: https://www.spiegel.de/netzwelt/netzpolitik/horst-seehofer-will-messenge
 \end{center}
 \begin{figure}
 	\centering
-	\includegraphics[width=10cm,height=6cm]{xkcd_password.png}
+	\includegraphics[height=6cm,keepaspectratio]{img/xkcd_password.png}
 	\label{}
 \end{figure}
 
@@ -191,7 +191,7 @@ http://xkcd.com
 
 \begin{figure}
 	\centering
-	\includegraphics[width=2.5cm,height=2.5cm]{wuerfel.jpg}
+	\includegraphics[height=2.5cm,keepaspectratio]{img/wuerfel.jpg}
 	\label{}
 \end{figure}
 
@@ -214,7 +214,7 @@ http://xkcd.com
 
 \begin{figure}
 	\centering
-	\includegraphics[width=7cm,height=7cm]{keepassx.png}
+	\includegraphics[width=7cm,keepaspectratio]{img/keepassx.png}
 	\label{}
 \end{figure}
 
@@ -227,7 +227,7 @@ http://xkcd.com
 
 \begin{figure}
 	\centering
-	\includegraphics[width=7cm,height=5cm]{pwgen.jpg}
+	\includegraphics[height=5cm,keepaspectratio]{img/pwgen.jpg}
 	\label{}
 \end{figure}
 
@@ -241,7 +241,7 @@ http://xkcd.com
 
 \begin{figure}
 	\centering
-	\includegraphics[width=7cm,height=5.5cm]{biometrie.jpg}
+	\includegraphics[height=5.5cm,keepaspectratio]{img/biometrie.jpg}
 	\label{}
 \end{figure}
 
@@ -269,7 +269,7 @@ https://media.ccc.de/v/biometrie-s8-iris-fun
 
 \begin{figure}
 	\centering
-	\includegraphics[width=7cm,height=5cm]{2FA1.jpg}
+	\includegraphics[height=5cm,keepaspectratio]{img/2FA1.jpg}
 	\label{}
 \end{figure}
 
@@ -282,7 +282,7 @@ https://media.ccc.de/v/biometrie-s8-iris-fun
 
 \begin{figure}
 	\centering
-	\includegraphics[width=7cm,height=5cm]{2FA2.jpeg}
+	\includegraphics[height=5cm,keepaspectratio]{img/2FA2.jpeg}
 	\label{}
 \end{figure}
 
@@ -409,4 +409,4 @@ Mal davon abgesehen, dass es echt uncool ist, eine Dienstleistung in Anspruch zu
 
 
 
-\end{document}
\ No newline at end of file
+\end{document}