[bob-e-reader]

Hello,

Description of the problem:


Convert a PDF file (<6MB) to MOBI, size of MOBY converted is about 80MB
Delete the PDF file from Calibre (so I know the newt conversion will be made from the MOBI file)
Convert the converted MOBI file to EPUB, size of the EPUB is about 25MB
Delete the MOBI file from Calibre (so I know the newt conversion will be made from the EPUB file)
Convert the EPUB into a MOBI file, size of the MOBI is about 25MB.

Questions:

1) Is that normal that a small PDF file will become 40 bigger when converted to MOBI?
2) Why is there such a difference between PDF-->MOBI and MOBI-->EPUB-->MOBI conversions?

3) As I explained in the description, I delete files so I'm sure the conversion is made from a determined base file (MOBI instead of PDF for exemple).
Is there a way telling Calibre what file format to use when converting from, and having more formats of the same file?

Thanks