# OS X: Blurry Beamer presentations on Sierra / High Sierra

Since OS X 10.12 (Sierra), the built-in Preview, but also many other PDF Viewers on OS X (such as Skim) show a number of problems, among them the following rendering issue:

• The page is first rendered in low-res with blurry text and graphics.
• About one second (!) later, the page is rendered in high fidelity.
• The display "wobbles", as text and graphics on the high-fidelity page is about one or two pixels up.

Example code:

\documentclass{beamer}
\begin{document}
\begin{frame}{Duke says}
\begin{itemize}
\item<+-> It don't mean a thing, if it ain't got that swing
\item<+-> (doo-ah, doo-ah, doo-ah, doo-ah, doo-ah, doo-ah, doo-ah, doo-ah)
\item<+-> It don't mean a thing all you got to do is sing
\item<+-> (doo-ah, doo-ah, doo-ah, doo-ah, doo-ah, doo-ah, doo-ah, doo-ah)
\end{itemize}

\end{frame}

\end{document}


While one may consider this acceptable when reading documents on screen, this is a show stopper for presenting beamer presentations with animations. The low-res display and wobbling makes the audience sick, while the 1 second rendering time makes PDF-based animations impossible.

So I am looking for a PDF Viewer for OS X that does not suffer this problems, but that a suitable for presenting beamer-based slide shows. Requirements:

1. page-wise full-screen/presenting mode with just the page and nothing else on the screen
2. crisp and high-fidelity display
3. quick rendering time

Unfortunately, the root of the problem is in Apple's own PDFKit library that is the base for most PDF viewers on OS X. So I am looking for PDF viewers that are not based on PDFKit, but fulfil the requirements above.

I am aware, of course, of Acrobat Reader DC. However, I do not particularly like its font rendering (Req 2) and I would also prefer something more light weight. I also have PDFExpert, which also is not PDFKit-based, however, does not support a presenting mode (Req 1).

• I have an even later version of MacOS Sierra (10.13.4), use preview regularly (at least twice a week) for beamer presentations and do (nor did) not have any of the issues described here. – user121799 May 13 '18 at 22:03
• @marmot: That sounds promising, as I am on 10.13.4 as well. I have added a short example. Even with this simple example the effect is visible after a page flip for 0.5 to 1 second on my MBP 13-inch, 2016. – Daniel May 14 '18 at 12:22
• Hmmh, in your document I get some really weird effect when viewing it in the full screen (not slide show) mode: the 2nd and 3rd slides are jammed together on one slide. However, for my own presentations I always use full screen and never had issues (even though they have up to 1000 frames). – user121799 May 14 '18 at 16:21
• Does this also happen for other latex generated documents or just beamer? – user36296 May 14 '18 at 16:45
• related question: apple.stackexchange.com/q/325622/57046 – user36296 May 17 '18 at 16:59

The delay in rendering pdfs with preview.app can be avoided with the following apps (they are all available through homebrew):

• Présentation.app: brew cask install presentation
• pdfpc: brew install pdfpc
• xpdf: brew install xpdf

• For those who prefer MacPorts: Currently MacPorts provides only the X11 versions, which do not work well for presenting full-screen mode. The homebrew variants are native. You can install them without doing any harm to your MacPorts setup.
• The graphical Présentation.app and the console-based pdfpc assume a dual-screen setup and provide a presenter display with the next slide, elapsed time and so on. Both internally pre-render the PDF pages. Depending on the complexity of the slides (transparencies have quite an impact), this may take a while. However, the presentation output is superb.
• Apparently, xpdf does not do pre-rendering. While it is fast in general, switching to a new slide causes flicker.