Hi everyone!

I'm trying to convert a PDF (which scrolls awfully slow on my MBA, although the size is only 12mb) into a mobi, so that I can read it on my kindle. The conversion takes about 10-15minutes and sending it to the kindle works like a charm. However on my kindle the mobi behaves like a PDF. I can't change the text size (it's all zoomed out like a PDF), which makes the document useless. What can I do here?

Best,
Ernesto

That's because your PDF is a bunch of scans (images) of the pages not actual text. You have to find an alternative source of the document.

Thanks for the response, Kovid!

A little googling brought me the solution, for the people looking for one.

If you have the Pro edition of Adobe Acrobat, you can OCR the text, even after it has been scanned. It takes a little time (since it analyzes every page from top to bottom) but it's definitely worth it. After the process, save it, re-put it into calibre, convert it (now the conversion doesn't take long at all), the file is way smaller (just 3mb) and it works perfectly on the kindle.