I saw this in Infinite too, but actually, all is alright: In Vue you set a certain render dimension, with 300 dpi, open in PS, and see that you actuallyhave a render that is at 72 dpi, and not 300, but the size is a lot bigger than the one you rendered at in Vue. So just do this: in PS, image, image size, change the dpi to 300, but be sure to uncheck resample, and voilà, a 300 dpi render at at the exact size you wanted.