Why are my pdf's being resized? Please help.

So I am at my wit's end and I've already had several people at work try to help but they can't figure it out either.

Here is the situation;
I'm using Photoshop CS2. I have created a document that is 8.5" x 11" at 400dpi CMYK. I've finished the project and want to make a PDF to take to the printers. I choose Save As, give it a name, select Photoshop PDF, and Save. No problem. If I reopen the document in Photoshop everything is fine and just as I made it. But if I open the same document with Acrobat and do a print preview my image is reduced down to about 3" x 4". So I'm looking at the 8.5" x 11" print page and my document is about a third of the page in the center. I have done this dozens of times in the past and I'm pulling my hair trying to figure out where things are going wrong now.

I have tried everything I can think of. What really confuses me is why the same document has different dimensions in different programs. In Photoshop the document is normal as it should be but the same document viewed in Acrobat is much smaller.

In the past I would just save whatever document I had going in Photoshop as a pdf and it kept the same dimensions.

What am I missing here, PLEASE?

Hum,

What are the print settings in Acrobat?

make sure that you don't have print to fit checked

Also make sure you have the same size paper selected in Acrobat (ie: 8.5"x11"). That will effect the print preview display window too.

What really confuses me is why the same document has different dimensions in different programs. In Photoshop the document is normal as it should be but the same document viewed in Acrobat is much smaller.

If you have "Preserve Photoshop Editing Capabilities" checked in the Save as PDF dialog, it is entirely possible to have different dimensions. In this situation, Photoshop preserves a complete copy of your image--complete with layer information, etc.--in a private section of the PDF. When you reopen the PDF in Photoshop, it uses this private info to recreate the document just as it was. Other applications, however, do not use this private info, and only see the "public" (i.e. non-private) image that is also stored in the file.

Here's where things can diverge. In the Save as PDF, you have the option to downsample the image, convert color space, etc. and these only affect the non-private image that gets written to the PDF. So it is entirely possible for the document to contain both the original 8.5 x 11 @400 ppi CMYK image (as private data available only to Photoshop), AND have the image itself appear to other applications at a lower resolution and/or different color space.

There is a bug in CS2 that when you do image downsampling as part of the Save as PDF process, it doesn't recompute the page size correctly, and that's why you're seeing a change in the page size (although the image still fills the page), which is another indication that you are resampling the image when saving as PDF. Perhaps you're using the "Smallest File Size" preset, for example.

My advice is to avoid the downsampling option in Save as PDF. If you need to downsample your image, do so manually before saving as a PDF.

Hope this helps.

Paul