Now I understand what you mean I am so accostumed that in the cine world normal = x2 the diagonal. e.g. 25mm for 16mm instead of the 12,7 etc.. sorry.
my bad. Btw. there are plenty of D to C mount adaptors that would allow you to use Century and Kinoptik Super wides for Super 8 and 16mm on many Super 8 and Standard 8 cameras. Not the fixed zoom ones though.

Again Entschuldige meinen Denkfehler.