What version of PDF should I be specifying when using pdfTeX? I know it defaults to 1.5, so that you can have object compression. Is there any reason I would want to raise this? For example, will I get a smaller file or such?
Alternatively, are there any interesting features that I could access by raising the version. I could see XeTeX and LuaTeX users wanting OpenType embedding (V1.6), while most of the things after v1.6 seem to be multimedia or encyption related, except for V1.7 which adds "new string types: PDFDocEncoded string, ASCII string, byte string" —Is this something that would improve my output files?
Will setting the minor version number higher then 7 improve my PDF output, or will it just cause incompatibility flags for people with outdated PDF readers? I'm also only really interested in things which I can take advantage of through LaTeX (i.e. pdfTeX supports it, or there is a marco package to add support for it). Theoretical features that I can't use are much less interesting.
Best Answer
If you include PDFs into your document, you should set it to the highest version of the included PDFs. Otherwise 1.5 is the highest version that will have any effect on the PDF generated by pdfTeX.