I have a crop body camera 1.6. My question is if I install a 50mm lens ,this changes to a field of view of that around a 80mm lense correct? So if I install the 1.4x teleconverter with the 50mm do I multiply 2 x 50 = 100 or is it 1.6x50 = 80 and then 80x1.4= 112? Which is the correct way to determine the field of view? Sorry if this makes no sense.