Black metal body. Yellow 'EE' markings. Metal focus grip. This is the original 7 element (in 7 groups) version, not the preset. The specific lens used in this test was manufactured in March of 1973 (code: 3B).
1970 - 73
Hexanon - C
The oldest version of the 28mm does seem sharper in the corners compared to the two later, non Konica, versions. It's a little unfortunate that this version gets the lowest hotspot score of the three, but it still hovers around 90%, which is very good. I have now managed to get some samples from this lens in strong lighting conditions and it really shines. I still need to test the original 24mm to see if it can stand up to the quality of this lens, but at the moment this is probably my favourite wide lens for IR. I have yet to test this lens for colour IR.