Lens c, cf, cfe

[lumar78]

I'm new to this forum, so I apologize if you ask something already asked in other topics.
I would like to know if there are real and tangible difference in quality between optical objectives "C", "CF" and "CFE", I know that among the different versions there are decades in other forums I have not answered that are dedicated all of excellent optics, since the price is not worth taking the "CFE", because the quality difference is negligible compared to the previous versions. Someone I can confirm this?
Thank you.

 

[blowupster]

There are more optical difference between a "CFE 40mm IF" and a (2001) CFE 40mm not IF. Than between a 1953 Sonar F 250mm/5.6 and actual Sonar Cfi 250mm/5.6 !

The 1956 Planar C 80mm and CFE 80mm share the same optical design. Improvments are single coated to multi coated and ergonomical. The 1952 Tessar 80mm/2.8 was not a great lens.
The 1947 Ektar 80mm/2.8 was better than Tessar.

 

[Emilio Esplanar]

Depends on the lens you want.

Same optical formula in all generation have: 30mm, 100mm, 150mm, 180mm, 250mm.

40mm: 3 formulas: C-Version (very large), FLE-Version (CF or CFi/CFe), IF Version (since 2006)

50mm: FLE was added during the CF-era, so there are CFs with and without FLE

60mm: Some older version existed, but all 60/3,5 share the same formula

80mm: Nearly all the same, except one very early version and the CB-version

120mm: Changed from f5,6 to f4 somewhen in the 70s. No changes since. The newer lens is better corrected for infinity.

Except for the 40mm, there have been no optical changes since the late 80s, so CF will be fully sufficient. In case of the 50mm, just make sure it has FLE, but older version was quite good either.
The 40mm IF is still very expensive, even second hand.