...a physical fact, too, the most delicate modelling and tonality is to be obtained in a medium light. From what has been previously said, it will now be...understood that a picture should not be quite sharply focussed in any part, for then it becomes false; it should be made just as sharp as the eye sees it...

...a physical fact, too, the most delicate modeling and tonality is to be obtained in a medium light. From what has been previously said, it will now be...for then it becomes false ; it should be made just so sharp as will best give the appearance of nature from one point of sight, and no sharper, for it...