I’ve got a designer freaking out because the photos I gave him are 180 PPI. “Photos have to be 300 DPI or they will look bad in print!”

Am I correct in thinking PPI does not equal DPI? We’re talking display vs. print. If I open an image in Photoshop and look at “image size,” it might tell me the image is 180 PPI and 8 x 10 inches. If I use that image in print but size it to 4 x 5, it seems to me I’ve effectively created 360 DPI.

If i’m wrong, please correct me!

You’re right.
The designer wants 300 DPI at the final size.