Opening AI file in acrobat artboards outsized

Question

When opening an illustrator file with acrobat, you can see one artboard per page.
But why is it that the size of each page is three times bigger than the original artboard?
Example: I have an ai file with multiple artboards of size 600x600, but when view with acrobat, they suddenly have a size of 2500x2500!
Is it possible to maintain the original artboard size in acrobat? If not, is it possible to resize the artboard images when exporting via acrobat?
The only method i know of now is:
Dim ojs As Object = pdfDoc.GetJSObject
     ojs.saveas("c:\temp\aaa\a.jpg", "com.adobe.acrobat.jpeg", False)
But i do not know how to resize them without color loss
Any help on this appreciated!
Version: CS6

Answer 1

Forget the idea that the artboard has a size in pixels. It doesn't by the time it's a PDF.
So you have a PDF with a size in inches and you save as JPEG. The size in pixels of the JPEG depends on that size in inches AND the resolution used to generate the JPEG. This resolution might be fixed in Acrobat or it might be an option, not sure, but I'm not hopeful it's an option.
I think you might find you had more control if you used Photoshop - quite possibly for the whole task, or if not, for opening the PDF - you can always set the image size and resolution before saving as JPEG.