Start by telling us your InDesign version and computer platform.
Select each image placed in InDesign and tell us what the Effective resolution is in the Info panel (Window > Info)
How are you viewing the PDF files? How are you measuring the file size of the PDF output?
1. I'm on a Mac OS Yosemite 10.10.5 and using the latest versions of all Adobe's software through the creative cloud.
2. There is only one large cmyk image. Both the real and the effective resolution are 300dpi
3. Viewing in Acrobat, but measuring by actual reported info. Plus e-mail to the client. He sees the same file sizes.
4. This is exactly the same for both of the documents I'm talking about. Yest one comes in at 2.4mb and the other at 14.2mb.
What PDF Preset did you use to create the PDF from InDesign? Did you use the same PDF preset on both InDesign files?
In #3, what do you mean by "measuring by actual reported info"?
What version of Acrobat are you using? Are you using the PDF Optimizer > Audit Space Usage?
Are you using Print Production > Output Preview > Object Inspector?
I've made a 2-page ID file and placed each ad on its own page. Then exported with exactly the same settings for each page. Same rtesults. It's got to be in the PSD file somhow, but I don't see how it's possible since both started from the same master layered PSD.
And, yes, both TIFs are flattened. :-)
"Reported Info" I mean ... File > Get Info PLUS My e-mail (Outlook) tells me file sizes when I attach them. Please believe me - I'm not a novice – been using photoshop since the early 90's. Never seen anything like this before.
All of my Adobe products are up to date according to the Cloud.
Okay, I just said I'm experienced, but I've never heard of "PDF Optimizer > Audit Space Usage?" -- OR -- "Print Production > Output Preview > Object Inspector?"
What – and where – are they?
Whoops. Forgot to answer your first question...
Exporting from ID PDF Preset "PDF/X-1a:2001" specified by the magazines.
You actually changed the pixels several times so there could be different things which happened: (1) You resized the PSD. (2) You converted from PSD to TIFF (which wasn't really necessary). (3) You also flattened the image. Each of those steps changed the pixels. (4) Then you placed the TIFF. (5) Then you exported a PDF using certain settings which might have changed the pixels. You may have done one of more of these steps differently between the two copies and not noticed.
The two utilities I mentioned in Acrobat gives you information about how the pixels appear in Acrobat. They are diagnostic tools. (Think CSI!) PDF Optimizer > Audit Space Usage examines the PDF and gives you an idea of how a PDF's file size is created. If there are differences between the two files it might give us a clue about what happened.
Print Production > Output Preview > Object Inspector shows how the image looks internally to Acrobat. Here's an example:
Here's what the Audit Space Usage dialog looks like for a multipage catalog with large images:
Thank you for the good info. Although I'm sure both PSDs came from the same source and I'm sure (after having tried several times) that I didn't export them differently, the utilities you mention in Acrobat sound like a good answer. Will try today.