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PDF documents are usually vector graphics and can be zoomed infinitely. Some PDFs like infographics contain a lot of information and need a large zoom to read them. Why can evince not zoom over 400%? Can it be set up to do a deeper zoom?

arauzo
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2 Answers2

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It seems an optimization in the use of memory. If the page cache size is increased, evince will allow larger zoom levels.

This can be done from the terminal, allowing to zoom up to around 2700%, with:

gsettings set org.gnome.Evince page-cache-size 2014

arauzo
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  • Are there a similar setting on Windows? If yes, where can I find it. – C-- Jan 14 '21 at 04:26
  • @Subin Sebastian Sorry, I don't know. Maybe you will have more luck asking in a windows forum (this is for Ubuntu). I don't even know if evince could be run on Windows. – arauzo Jan 14 '21 at 13:03
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    i rounded up from 2014 to 2048 and now it lets me go up to an even 3200% – Michael Sep 19 '21 at 23:05
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"The maximal zoom is constrained by page cache size".

So the maximum zoom level depends both of your page cache and the PDF itself (the heavier, the less zoom capability).
For info, display page cache size (50 by default) with

gsettings get org.gnome.Evince page-cache-size

Set it to a bigger value to be able to zoom more, for instance:

gsettings set org.gnome.Evince page-cache-size 2000
zx485
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CaptainBleuten
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  • so Evince renders the entire page at the specified zoom level and only shows a small portion? Seems like very bad design (even though evince is the best pdf reader I've found so far, better than xreader and the likes) – Mark Jeronimus Sep 18 '23 at 10:01
  • @ Mark Jeronimus Yes probably, and I guess there's no choice really. I haven't dived far enough into pdf file rendering, but what makes sense is, as it allows for vector rendering, it has to compute shapes described and then figure out which part is in the displayed area. (A problem that wouldn't occur with bitmap content) – CaptainBleuten Sep 25 '23 at 13:26
  • I noticed that Firefox' build-in PDF renderer has a limited framebuffer too, and when you zoom beyond that, it just displays the framebuffer enlarged (i.e. blurry). They could have implemented that. – Mark Jeronimus Sep 27 '23 at 09:34