Componon-S 2.8/50mm Variations

[themoleman342]

I have two Componon-S 2.8/50mms. Lever aperture. Green ring. Bodies look absolutely identical. One is from ~1983, according to the serial number, and the other is from ~1994.

1983 Version:
Front element is bigger in comparison to '94 model
Aperture blades form a 5-point star shape
@f2.8 the aperture blades do not fully retract - still visible in lens path - common with enlarger lenses
Back element sticks out 3mm past the mount

1994 Version:
Aperture blades form a typical hexagon
@f2.8 the aperture blades are not visible
Back element sticks out 6mm past the mount

The focus point is completely different between the lenses. The '94 version focuses considerably closer. Coatings looks almost identical.

Can anyone account for any of these changes? Anyone see an advantage of one over the other?

[patrickh]

I have three versions of the 100/5.6 and all three are completely different in make-up. I think they were constantly revising design for improvement and special uses.


patrickh

[ZoneV]

I suppose ROHS update to leadfree (and other hazardous things) glass.
This ROHS is a big problem for optics industry, because it is much effort to redesign lenses without these old glass with lead and such.
On a optics fair I visited I learned that optics industry (e.g. Schott) here in Germany still tries to get expeptions for optics.

Regaring the aperture I suppose the newer aperture is easier (cheaper) to build.
I love enlarger lenses - but don´t like the plastic iris housing on some newer ones, like Apo Rodagon D 75mm/4 :-/

[themoleman342]

That's interesting! Have you ever noticed a performance difference between the older lead-based designs and the new lead-free ones?