Are you talking about the File - File Info panel?
What version of Photoshop are you using?
Look for these fields to give you an idea of the resolution of the imager in the camera... The Canon EOS-40D, for example, has a 3888 x 2592 photosite imager and shows the following.
| <exif:FocalPlaneXResolution>3888000/876</exif:FocalPlaneXResolution> | |
| <exif:FocalPlaneYResolution>2592000/583</exif:FocalPlaneYResolution> |
See also: Exif TIFF Tag FocalPlaneXResolution, code 41486 (0xA20E)
I found the above stored in a small JPEG that I had converted with Camera Raw to 6144 x 4096 pixels then processed.
-Noel
