A quick suggestion to RAP's reply - It should be noted that the photographers he mentions (Barnbaum, Sexton, Adams) all shot or shoot large format. If ytou are shooting smaller format you might find that these ratings are not in line with what you desire. Its always best to take the film for a "test drive" meaning - shot, develop and print on the grade you like and at the size you wish to print. If it is not correct, then make your adjustments accordingly.