I know that a 50 mm lens in 24x36 format is similar to a 80 mm one in 6x6 format. I want to know which lenses would be equivalent to 28 mm, 105 mm and 135 mm. Additionally, I would appreciate your recommendations for my Hasselblad 501CM. I already have the 80 F2.8 CFT lens, but I do not know which angular and tele I should get. Thank you, Henry.