I need advice for selecting lens for shooting portrait in 4x5 and 8x10. In 35 mm usually 85 mm lens considered as portrait lens and I like the way it sh ow the face. And for 4x5 ,85 mm will be about 300mm,8x10 about 480mm. Some phot ographer like Karsh ,Ive heard that he is useing mainly 300 mm for 8x10 or 5x7 . In general 300 mm considered as good lens for portrait ?