250mm Sonnar Question

[ubarw]

HI again...

A question about a lens... One of my lenses is a 5.6 250mm, Sonnar. I do not see the T* on it.

I researched this some time ago, and if I remember right the t* referred to the glass type? Wrong? Right?

I am downloading manuals on all this stuff, and want to know if the manual for the T* is close enough...

Thanks!

 

[sportback]

'T*' simply refers to Zeiss multicoating - the physical architecture of the lens itself doesn't change. The silver bodied lenses in your setup could be with or without T* coating, but as a rule of thumb, the black bodied lenses tend to all be coated.

Nice setup, by the way!

 

[ubarw]

Roger dodger!
Thanks!

 

[wbulte]

Another rule of thumb: the shorter the focal length, the more desirable improved coating like T* becomes.

Wilko

 

[fish_shooter]

Chrome T*

Only a few chrome lenses were made T*. Most chrome lenses are from earlier. The lens line when all black before the lens line went all T* so there are black lenses without T*. The 250 5.6 Sonnar formula dates back to the original focal plane shutter camera series from around 1954.

 

[polypal]

T* coating.

As a rule of thumb most black C lenses have T* coating.
Exceptions: 100 mm Planar, 150 mm Sonnar, 500 Tele Tessar.

The opposite silver C lenses do not have T* is only partly true:
A small amount of the 50 mm Distagon in silver were fitted with T* coated elements.
The quantity of T* silver 80 mm lenses is much larger but still rare.

I own two T* coated silver lenses that were fitted later in their life with T* glass: a 150 Sonnar and a 250 Sonnar.

 

[fish_shooter]

As a rule of thumb most black C lenses have T* coating.
Exceptions: 100 mm Planar, 150 mm Sonnar, 500 Tele Tessar.

The opposite silver C lenses do not have T* is only partly true:
A small amount of the 50 mm Distagon in silver were fitted with T* coated elements.
The quantity of T* silver 80 mm lenses is much larger but still rare.

I own two T* coated silver lenses that were fitted later in their life with T* glass: a 150 Sonnar and a 250 Sonnar.

I bought a new 50 C Dist in 1974 that was chrome and T*. I later traded it to friend for a 40 C T* that I sold still later.

Lenses made in the 60's that were black are not T* since it was not yet invented such as the 500 and 40. Interesting is that there are some early 500's that were part chrome. I have seen some of these. There is a brochure showing a part chrome 40 but none of the annual catalogs show it - a pre-production lens that was shot for the brochure ???

Interesting that you were able to get some old lenses updated with T* coating!!!

 

[wbulte]

I

Interesting that you were able to get some old lenses updated with T* coating!!!

Well, the glass is identical, just the coating differs. That makes swapping lens elements all that is required. Not too difficult.

Wilko

 

[polypal]

Lenses made in the 60's that were black are not T* since it was not yet invented such as the 500 and 40.

Interesting that you were able to get some old lenses updated with T* coating!!!

It is not well known that multi coating is much older.
Carl Zeiss used it on some pre war lenses but never bothered to make it a commercial selling argument untill it was applied with lenses made for Hasselblad cameras in the seventies.

Some lenses like the 100 mm Planar had the same glass elements starting with early non T coated C lenses through the latest CFi versions.

 

[wbulte]

It is not well known that multi coating is much older.
Carl Zeiss used it on some pre war lenses but never bothered to make it a commercial selling argument untill it was applied with lenses made for Hasselblad cameras in the seventies.

Some lenses like the 100 mm Planar had the same glass elements starting with early non T coated C lenses through the latest CFi versions.

Pre-WW2 and most likely during WW2 as well MC was a military secret, maybe that is a reason?

 

[fish_shooter]

Well, the glass is identical, just the coating differs. That makes swapping lens elements all that is required. Not too difficult.

Wilko

Very clever of CZ to do this! Quite different from Leitz. For example, I understand that the construction of just one lens, the 50mm f/1.0 Noctilux had several variants. This included how the lenses were constructed on the inside - edges cut differently - so this kind of swapping is not possible.

 

[polypal]

Pre-WW2 and most likely during WW2 as well MC was a military secret, maybe that is a reason?

In suppose everything German manufacturers developped in those days was a military secret.
Engineers at CZ simply did not bother about the discovery multi coating improved certain characteristics of lenses.
Once the Japanese found out what Multi Coating could do the commercial potential of MC became clear to Carl Zeiss management.


Paul