Ripping a PS or PDF?

[rickself]

I've been messing around, trying to get a PDF file (created in InDesign) that takes 30 minutes to RIP, to RIP faster. I don't know, kinda quiet this week, time on my hands. So I found that if I take the same file that I have made PDF and create an in-rip separation .ps file, the file rips in 3 minutes, rather than 30. The preview on the Xitron Navigator appears identical to the PDF file. It seems that after doing this for 25 years, I should have the answer, but...
In a PDF workflow, why can't I just postscript the file using the XitronRIP.ppd and save the steps of compressing, interpreting and de-interpreting? Am I missing something?

[DCurry]

First thing that comes to mind is transparency - does the PDF have live transparency anywhere? If so, it gets flattened during postscripting so that might explain the difference.

Also, is trapping included in your rip time? If so, what happens when you turn it off?

[Joe]

First thing that comes to mind is transparency - does the PDF have live transparency anywhere? If so, it gets flattened during postscripting so that might explain the difference.

Also, is trapping included in your rip time? If so, what happens when you turn it off?

This! Many times designers create files with about a billion paths in it and trapping will slow it down greatly. If you ps/distill it many of those paths will be rasterized if they are touching transparency. So then they RIP faster.

[rickself]

As far as trapping, believe it or not, I still manually trap my files. The boss has so far figured my time is less expensive than the $3000 plug-in.
And transparency, yes, I did notice that the transparency is different when postscripted. I would suppose (brilliant) that may be why the rip time is so fast but also thought there may be a setting I am missing! I use the XitronRIP.ppd to postscript and will do more examination of the settings.
See, that's why I can ask these questions here - so I can be slapped upside the head and not take offense.
Like I said, I'm filling time on a quiet week, making the brain cells buzz.

[DCurry]

If it were me, I would let the PDF take as long as it needs rather than making the .ps file. I don't like the idea of flattening transparency unless absolutely necessary.

[rickself]

Agreed. Just made me wonder why the difference in times. Transparency says it all.