OK,I'm back with some results.
To see the pictures full screen without zoom it is hard to distinguish between files having a resolution of 754x566 pixels or greater.
When you zoom in to the max of the zoom factor, you can see that certain artifacts (pixels) are not visible on the lower qualities, but they are at 800x600 resolution.
Upon review I'll have to recode the images,seeing that the 779x548 pix. image is way blurrier than the 800x600 image.
This can have to do with the encoding being set to retain 84% of the original quality.
Tomorrow I'll re-post everything on 100% quality.