New to self-publishing. I have a mac pro, and using Pages to write the manuscript.
I have inserted a number of images, that are at a resolution of 300dpi, however, when I convert the manuscript to .pdf for acceptance by Amazon KDP,
the images are automatically reduced to 72 or 79 dpi?
So of course, AmazonKDP will not accept the manuscript and images, because the images are not 300dpi.
Is there anything I can do to make sure the images are locked at 300dpi when converted into .pdf, without having to purchase any expensive program to sort this problem out?
I can't help with Pages but the free program OpenOffice Writer will produce a PDF at 300 dpi. This is what I used to make my book. I have since discovered Word may be able to do the same using the "Print to PDF" option rather than Save As but I haven't given this a try yet. I guess you could copy and paste your book into OO Writer but you will have to learn how it does things - but it is more or less a typical word processor.
The alternative would be to see if there is any function for "Printing to PDF" with Pages. This, if it has it, will be different to a Save as or Export command.
Many of the MS Word "PDF converters" produce a PDF of 200 or even less DPI. From what I've seen this is fixed and can't be adjusted/increased. To overcome this run the WORD doc through one of the free available PDF creation utilities that can be downloaded from the web, such as CUTE PDF.
Ignore the advice to use another program. The Mac OS print workflow is built around a PDF engine, so it's perfectly capable of giving you high-resolution PDF files. Of course, if your original images weren't at least 300 dpi, nothing is going to help.
If any of your images contain transparency, then you may get better results with using the Print menu and saving as PDF, rather than the Export menu from Pages.