Quote:
Originally Posted by adrhc
PB90x and PRS 505 are also identical when reading technical PDFs ?
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I should first point out that my PB 902 is running an older version of the firmware (2.0.4), so it's possible that newer versions will produce better results.
The 902 has twice the screen area of the 505, so it can render the characters larger (which helps a lot). If I put the 505 in landscape mode and the 902 in portrait mode, then the widths of the screens are similar. Comparing the same Latex-generated PDF file, it looks like the rendering on the 505 is slightly darker than on the 902. The fonts are tiny, though, so it isn't easy to read on either one. Using the 902 in landscape mode makes it much easier to read the PDF file.
Knowing how PDF files work, I don't think you can just replace one font with another when drawing. The characters are placed precisely in positions that give a nice result for the particular font specified in the document. Rendering with a different font will produce ugly spacing (and even overlapping) between the characters. If you want to use a different font, you have to rebuild the whole PDF from source to get the character spacing (i.e. kerning) right. That's why you don't generally see an option to use different fonts in PDF viewers.
Fonts used in PDFs are generally optimized for ink on paper (i.e. high resolution and contrast). Hence, PDFs rendered on current E-Ink technology are usually difficult to read unless they have been created specifically for such devices. I don't think there is any E-Ink reader out there now that can do a really good job of rendering technical PDF documents. We have to wait for higher resolution and contrast E-Ink technology. For me personally, I can tolerate reading letter-sized PDFs on my 902 in landscape mode, but I definitely get more eye-strain than when reading an EPUB version of the same file.
I don't have a good digital camera, but I took a few 'pictures' of my 902 on my scanner at 600 dpi resolution. The colours in the scans don't look right on my monitor (the background is darker in the images), but it gives a good idea of how the characters are rendered. I took a scan of an EPUB for comparison, and a Latex-generated PDF and an O'Reilly PDF both in portrait and landscape modes. You can download it from:
http://www3.telus.net/rkomar/PB902-scans.tgz, but be warned that the file is about 50 MB in size.
Edit: I should note that I used AdobeViewer for all the scans.