Canon FD 135 2.5 vs New FD 135 2.8

Interesting that you brought that FL lens into the discussion too. I may try both in comparison.
The FL 3.5 version is of the respective Sonnar design, which made it into the FD mount too.

The Canon FD 135mm f3.5 lenses are only 4 element lenses, the f2.5 and f2.8 versions are 6 element lenses.

That is not surprising. A larger aperture typically needs more elements to keep image quality.
And the classic, 1932 135mm-Sonnar design referred to was a 4 element design too.

AgX said:

That is not surprising. A larger aperture typically needs more elements to keep image quality.
And the classic, 1932 135mm-Sonnar design referred to was a 4 element design too.

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I have the new FD 3.5 and 2.8 lenses they are both very sharp but the f 2.8 one is overall a better lens I.M.O.I have never used the 135 f2.5 lenses or ever wanted one because the barrels are all metal, and I prefer the lightness of the polymer barrels of the new type FD lenses.
All my lenses are except one are all the new FD type and it makes a considerable difference if you are lugging a bag full of them around (that many photographers did before zoom lenses were any good) which at the time that polymer barrels came out Canon said was one of their reasons for discontinuing the metal ones.
I recall at the time the new FD lenses came out many Canon FD users were very pissed off about it, but speaking personally I have been using the "plastic fantastic" Canon FD lenses for more than 35 years all of which I bought second hand, and I have never had any problems with any of them.

AgX said:

Interesting that you brought that FL lens into the discussion too. I may try both in comparison.
The FL 3.5 version is of the respective Sonnar design, which made it into the FD mount too.

Click to expand...

Canon took the 135mm lenses seriously and thus redesigned them many times.

For the f3.5 versions:

FL 135/3.5 is optically the same as FD 135/3.5 chrome nose and the first S.C version, then in mid 1970s it changes from 4/3 design to 4/4 design. This later design is carried over to the FD new 135/3.5.

for the 2.5 versions:

R 135/2.5 and FL 135/2.5 are optically the same, FD 135/2.5 is a different optical design. The R/FL version is noted for very smooth bokeh. It's also horribly heavy and big. The FD is well liked.

for the 2.8 versions:

This is a new design, FDn 135/2.8. I used it professionally in the early 2000s and always gave me great results.

I've owned most of the lenses listed, and finally kept the FDn 135/3.5, which is very small, light, and optically very good.

flavio81 said:

Canon took the 135mm lenses seriously and thus redesigned them many times.

For the f3.5 versions:

FL 135/3.5 is optically the same as FD 135/3.5 chrome nose and the first S.C version, then in mid 1970s it changes from 4/3 design to 4/4 design. This later design is carried over to the FD new 135/3.5.

for the 2.5 versions:

R 135/2.5 and FL 135/2.5 are optically the same, FD 135/2.5 is a different optical design. The R/FL version is noted for very smooth bokeh. It's also horribly heavy and big. The FD is well liked.

for the 2.8 versions:

This is a new design, FDn 135/2.8. I used it professionally in the early 2000s and always gave me great results.

I've owned most of the lenses listed, and finally kept the FDn 135/3.5, which is very small, light, and optically very good.

Click to expand...

My Canon FD 135 mm f 3.5 lens has serious fungus, but I can't bring myself to throw it away.

flavio81 said:

Canon took the 135mm lenses seriously and thus redesigned them many times.

For the f3.5 versions:

FL 135/3.5 is optically the same as FD 135/3.5 chrome nose and the first S.C version, then in mid 1970s it changes from 4/3 design to 4/4 design. This later design is carried over to the FD new 135/3.5.

for the 2.5 versions:

R 135/2.5 and FL 135/2.5 are optically the same, FD 135/2.5 is a different optical design. The R/FL version is noted for very smooth bokeh. It's also horribly heavy and big. The FD is well liked.

for the 2.8 versions:

This is a new design, FDn 135/2.8. I used it professionally in the early 2000s and always gave me great results.

I've owned most of the lenses listed, and finally kept the FDn 135/3.5, which is very small, light, and optically very good.

Click to expand...

The biggest advantage of the FDn 135mm f2.8 against the 135 f2.5 optics is its SSC multi-coated and it is considerably lighter in weight, the 2.8 version being 390g, and the 2.5 one 630g.