How different are Tessars from different companies?

[Bernice Loui]

Spend some time with this Zeiss publication on Tessar lens design and history. It is a nice illustration of how design evolution happens and the FACT glass types alone does not make or break an given design as glass or plastic or similar refractive material is just one aspect of an overall optic design.

Notable is how aspheric surfaces were used to enhance the overall optical performance of the design for a mobile device camera with a designed image circle of 4mm. Another design requirement for a digital camera used in mobile devices is to incorporate part of the antialiasing filter into the design of the optic making the system more specialized while improving overall system performance. Add software to this system and it's no wonder why mobile device cameras have the level of performance they do today.

The idea of incorporating part of the antialiasing filter into the optic was mentioned to me by a friend who worked on a video camera decades ago when they contracted Angénieux to design and build a video zoom lens specific to this video camera to work with the electronic antialiasing filters in the camera. The resulting image system was excellent.

Point being to believe glass choice or glass type alone IS the determinate factor in the overall performance of any optic and imaging system is absurd.



Bernice

BTW, Zeiss notes about the Tessar:

Simply the advances in glass technology, similar to the time of its birth, enabled performance increases which also demonstrate the potential of the basic idea. From the outside, a Tessar from 1920 looks exactly the same as one from 1965, but the image quality of the newer lens is considerably better.

Lots of history here:

https://lenspire.zeiss.com/photo/app...ar-2011-EN.pdf

[Tin Can]

Very interesting Bernice, thank you

[MAubrey]

Spend some time with this Zeiss publication on Tessar lens design and history. It is a nice illustration of how design evolution happens and the FACT glass types alone does not make or break an given design as glass or plastic or similar refractive material is just one aspect of an overall optic design.

Notable is how aspheric surfaces were used to enhance the overall optical performance of the design for a mobile device camera with a designed image circle of 4mm. Another design requirement for a digital camera used in mobile devices is to incorporate part of the antialiasing filter into the design of the optic making the system more specialized while improving overall system performance. Add software to this system and it's no wonder why mobile device cameras have the level of performance they do today.

The idea of incorporating part of the antialiasing filter into the optic was mentioned to me by a friend who worked on a video camera decades ago when they contracted Angénieux to design and build a video zoom lens specific to this video camera to work with the electronic antialiasing filters in the camera. The resulting image system was excellent.

Point being to believe glass choice or glass type alone IS the determinate factor in the overall performance of any optic and imaging system is absurd.



Bernice

Zeiss has another article on this very topic!

https://lenspire.zeiss.com/photo/app...ile-phones.pdf

[Ron (Netherlands)]

Zeiss has another article on this very topic!

https://lenspire.zeiss.com/photo/app...ile-phones.pdf

hmm....this isn't about Tessars anymore and IMHO there have not been made any Tessars with aspheric surfaces nor been made of pressed glass.

[MAubrey]

hmm....this isn't about Tessars anymore and IMHO there have not been made any Tessars with aspheric surfaces nor been made of pressed glass.

Correct on both counts!

[Drew Wiley]

Tessars, generically, might very well have been made of molded plastic or hybrid components for modern small amateur camera applications. I'm not going to bother to research that either way, because this discussion is centered around LF applications.