Print Res Unchecked, Image does not match native resoltuion

Question

Many of my images already have their resolution and height/width dimensions set in PS. My understanding is that when the print resolution checkbox is unchecked in LR, then the image should be at its native resolution and size and will print the same size as when printed from PS.
However, I find that when I uncheck the resolution checkbox, the image size as shown in LR Print module does not match the native resolution and size. For example a psd file in PS CS3 shows an image size of 16 x 10.25 @ 200 ppi. In LR the same image shows a print size of 15.3 x 9.81 @ 209 ppi. I have checked both tif and psd files, and similar discrepancies exist.
I wonder if I am doing something wrong or misunderstanding something? Thanks for your help

Answer 1

That was Page Setup, sorry (which actually opens a Print Setup dialogue, at least on a PC). There you can choose printer and paper size. Then in Layout panel you choose how to arrange the picture(s) within the page, and the combination of the two will determine the print size, right?
Anyway, I believe I understand your concern now, which is about printing at 100% of the size indicated by the TIFF or PSD file, as PS can do. I did not find a way to direct LR to do the same.
The Print Resolution, when unchecked, doesn't behave like you expect. If you check it, LR will re-sample the image to print it at the resolution you indicated there, whatever the output size. If you un-check it, LR will not re-sample the image; still it will re-size it based on your Page Setup and Layour settings, and the printer driver/printer will do the needed re-sampling. At least this is my understanding.