iPad2 Optimum Import Resolution

I am trying determine for a bunch of folks what to recommend as the highest resolution for pictures IMPORTED into an iPad2 before greater resolution is of no use. Especially because they want to zoom in on different parts of images to show detail of the product in the image. Both imported JPEG's and also images that may be "embedded" in a PDF file.

I have taken (with my Olympus E-520 DSLR) files from 26MB down to 1.5MB. They all look good, and when I zoom in on my iPad2 they all kind of lose clarity relatively equally.

I do see that the 26meg image is better than 1.5 meg image upon zooming in, but it's not a tremendous difference.

Also, if my iPad2 is connected to a larger screen HDTV does the resolution come into play here, als???. If it does this may be a better and more critical arena.

RedStarBlackRose