macospdfpreview
A friend sent me a PDF with a UI mockup claiming it is 1024×768.
It is, indeed:
However, View > Actual Size (⌘0) zooms in so much that the PDF takes up almost all 1920×1200 screen estate that is available.
How do I view the PDF at its original size?
This works for me on Mountain Lion:
Open all the JPG's in Preview so that the files are selectable within the one window, i.e. thumbnails of the JPG's are viewable in the selection pane located the window's left side.
Click in the selection pane and select all the thumbnails with Cmd-A.
Select File > Print... from the menu bar.
Select PDF > (from the drop down) Save as PDF... from within the Print Dialog.
Take it from there...
Best is to reduce the photos before they are added to Pages.
For printing they do not have to be more than 300 dpi.
For viewing on the screen about 75 - 100 dpi.
Pages doesn't do the job as you found out.
You can do it in Preview > tools > Adjust size (on a Mac)
If do not ant to leave the iPad then you can use one of the many external apps to do it.
Additional Info:
The Resolution has the biggest impact on the file size, not so the size of the image.
Best Answer
Turns out, there's a Preview preference that controls what actual size actually means:
If you want points to correspond directly to physical pixels, choose the first option.
(Not sure how it affects Retina displays though!)