Sounds about right. The images are compressed in a PDF.
Thanks Bob! Is this going to be a problem with printing or will the resolution high enough? Is there a way to send IDD files full size?
You can open the file in Acrobat Pro and right click the image and choose to edit it. It should open in Photoshop where you can check the resolution.
There should be very little reason to worry. In fact, I’d be way more worried about sending an InDesign file than a properly created PDF.