Question about the 90/4 Rokkor-M (CLE version) optical design

[awilder]

Other than the multi-coating, is the optical layout the same on the CLE version of the 90/4 Rokkor-M as the prior 90/4 Elmar-C? I know about the cam difference but was more curious to know if Minolta kept the same formula as used in the Leitz version.

 

[Palaeoboy]

Although they share the same basic 4 element design they are not identical as Minolta did make changes. The resolution figures in reviews when new bare this out. The Minolta version has a more even resolution from centre to edge so slightly sharper in the corners than the Leitz version. The Leitz version however is sharper than the Minolta version in the centre but less at the edges. I would however note this is a slight tweak, I wouldn't call the difference as overly substantial.

 

[awilder]

So are these minor changes in the design that would not look different than the Leitz version in a cross sectional block diagram but the mathmatical changes in the curves and glass composition led to more even performance across the frame?

 

[Graham Line]

Same block diagram. I've used both and the Minolta version's rendering is more even across the frame. Whether the Leica looks significantly sharper in the center in normal use I can't recall, but Palaeoboy is right 99.999% of the time.

 

[back alley]

both are very nice lenses...

 

[awilder]

Thanks all.