I know the FL's were fine and they sold well but why did Zeiss change back to magnesium? Because it is less expensive to use magnesium or is it that people want magnesium and it is all about marketing like CJ says?
I would not say that Zeiss changed back
to magnesium. I would say that Zeiss was simply changing to
magnesium which is a lighter weight but more expensive metal to use in binocular frames. Zeiss's FL series larger binoculars got their weight from the large AK prisms they used; otherwise the Carbon Fibre bodies they had were both lightweight and strong.
And when I compare the weights of my (carbon fibre bodied) Zeiss Victory 7x42 FL T* and my Swarovski 7x42 SLC B the Zeiss is much
lighter in weight than the Swarovski is.