eReader PDF comparison 2

In this review, I compare the Kobo Aura HD and Kindle Paperwhite e-ink readers in a test of performance with PDF format files.  I look at native PDF as well as scanned PDF files on both devices, and I’ll talk about how I’ve learned to optimize the difficult task of working with an ereader PDF setup.


It’s not just the screen size of the Aura HD that makes it so much better at handling PDF files, it’s the ability to control zoom.

One of the most vital functions of an e-ink reader tablet for use afield is the ability to work with PDF files.  Since the advent of the Kindle, I have been very interested in the light weight and low power use of e-ink screens, but viewing of PDF files is the main concern I have.  Both of these devices have superb ebook reading features and functions.  The real difference comes in the ability to work with and read from PDF files.

The Kindle Paperwhite display is 6 inches, 1024 x 768, 212 dots per inch.  The Kobo Aura HD display is 6.8 inches, 1440 x 1080, 265 dots per inch.  Both displays have a 16-grayscale palette.  Both devices have LED backlight, similar performance with glare and sunlight, and similar touch screen functionality.  When viewing PDF files, the Paperwhite screen is incredibly fast, the Aura HD screen is slow, but the crucial difference is in resolution and size.

The larger size and higher resolution of the Aura HD is a huge improvement in viewing of any PDF files on such a small display.  Another major improvement in the Aura HD is the ability to zoom in smaller increments.  This allows you to zoom to the visible area of a page and eliminate any wasted margin space.  In the Paperwhite PDF viewing mode, zoom increments are much larger, and the first zoom increment will always crop off text and graphics.


The added resolution of the ClarityScreen+ in the Aura HD makes the crucial difference in readability of scanned PDF files

However, both devices present difficulties when viewing the PDF in a zoomed view.  The difficulties become apparent when trying to change pages while zoomed.  The Paperwhite will not page turn, but instead try to continue to pan, so it’s necessary to zoom back out when changing pages.  The Aura HD will page turn, but it takes you to a pan region in the upper left hand corner of the document, which will require dragging the pan extent back over the area of visible content.

The solution I have found is to use PDF files with a 3/4 aspect ratio.  On both devices, a 3/4 aspect makes a big difference in display quality of PDF files.  On the Aura HD, the 3/4 aspect ratio allows you to quickly set “fit width” in the view setting.  This 3/4 aspect ratio can be 6″ x 8″ or 6.9375″ by 9.25″ or 18″ by 24″… it doesn’t matter, so long as the size meets the 3/4 ratio.  This requires pre-editing the PDF files with a PDF editor, and using Acrobat was no piece of cake… it’s a lot of work but it makes a huge improvement.  (In Acrobat 11, go to Tools > Print Production > Set Page Boxes, and be ready to google “The page cannot be reduced in size”.  I found that sometimes I have to increase page size first, then perform the Set Page Boxes operation again to set the crop margins and get a viewable crop in 3/4 aspect ratio.  Even if this works, you must ensure that the first page is the correct size, and if it is not, you have to insert a blank page lower down on the page list so that it adopts the size of a correctly formatted page, then drag the page to the top and cut and paste your cover graphics into the new page.  Scanned PDF’s are the easiest, native PDF’s often throw an error… good luck and Google well.)

For my purposes, I want to use an e-ink reader to replace a couple plant ID field guides with a library of field guides, textbooks, and novels that I can carry with me on my long forays into wilderness.  The Kobo Aura HD fulfills this purpose, because of its ability to display PDF files, especially scanned PDFs, with the quality and control needed.  The screen size is very small and viewing of larger format textbook pages will require use of landscape mode and panning through the page, but using scanned PDF of typical book size of 8″ tall or less is possible on the Kobo.

Watch my video below where I demonstrate the PDF handling capabilities of each device, side by side!

2 thoughts on “eReader PDF comparison

  1. Reply katsumii Apr 17,2014 08:45

    Nice post, apeoid. 10/10 very informative, would read again.
    E-ink is the future!

  2. Reply coolvampireguy Oct 5,2014 03:07

    I was wondering: how come you don’t mention the fact that on the Kobo there is no direct dictionary-lookup functionality for native PDF files, whilst there is on the PW?

    Your article is still very helpful, but I think this is a useful piece of information you are omitting, especially to people wanting to read in different languages.

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