I am working with a colleague scanning some archive 10x8 inch photos. I have convinced him to scan inTIF at 600 dpi. The resulting TIF file is about 60 MB. We make a few retouches and then he wants to save it in JPG as it is then only 4MB. I know that there is something inherently wrong in doing this but he has opened the 2 resulting files, compared the pixels and sees no difference, and it is true seen like that, there is not much noticeable difference on the screen between the two.
Any enlightenment please?