zeiss naming conventions

hi all

 

i searched forums and could not find anything, so i thought i'd

throw this out to you: what do the names mean (if anything)?

superchromat seems indicative of superior chromatic fidelity,

planar nits at a flatness-of-field, distagon perhaps something to

do with shooting landscapes? tessar a loose connection to

tesla? i'm just curious if they have any meaning or if they're little

more than differentiators.

 

cordially yours. . .

Cool question :-)

 

At least, I can clear up the following: The TRIOtar is a three element lens, and tessar is four elements, since four in greek is "tessera" (No guarantee for correct greek spelling - but it's pronounced like that).

 

And the Leica "Hektor" lens was named after the dog of Max Berek, who designed it :-)

 

Look forward to seeing the responses...

Actually the names such as Planar, Sonnar, Distagon ... are related to the lens deisgn. For example, Distagons are retro-focus wide angles for SLRs while Biogons are wide angles with a symmetrical optical design that would have intruded into where the mirror box should have been. Therefore, Biogons are only for range finders (or non SLRs). The following page on Zeiss's web site: <A HREF="http://www.zeiss.de/C12567A8003B58B9?Open">http://www.zeiss.de/C12567A8003B58B9?Open</A> has the details. When you get to that page, click on "Lens Names" near the center of the page.

Rudolf Kingslake's books 'History of the Photographic Lens' and 'Optics in Photography' are excellent sources for many lens designations... and some amusing old designs. One odd design: the 'Goerz Hypergon lens of 1900' had a little cogwheel in front of the lens that was spun with air pressure to serve as a center weighted filter.

Yah, yah, but I thought maybe Charlie was asking how they arrived at these names. How did they coin them? You might imagine, for instance, that they though of 'Distagon' because the retrofocus design makes the lens more *distant* from the film plane.

 

Any more thoughts or guesses?

<p>Try this <a

href="http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&fra

me=right&th=6e466ea038ec3902&seekm=3B3C9BED.DC58DF

84%40attglobal.net#link10">message</a>, and the followups in

the thread, from rec.photo.darkroom.</p>

 

<p>(For those reading this as an email, the link is too long to

post, but do a search on "Wollensak Raptor vs. Pro Raptor" at

Google groups and it'll be the only hit.)</p>

 

<p>"Superachromat" is a technical terms in optics, meaning that

four colours are brought to a focus at the same plane. Glasses

bend different colours of light by different amounts, an effect

called dispersion, so to get the colours to focus in the same

place you have to use two different types of glass and get their

colour spreading effects to cancel. The simplest attempt at

doing this is the famous crown+flint doublet, which focusses two

colours in the same place and is called an 'achromat'.

'Apochromat' lenses focus three colours in one place (hence

their use in making seperations in graphics arts work) and

'Superachromats' focus four colours together.</p>

 

<p>"Apochromatic" is a term that has been redefined by the

photographic industry for its own purposes, so the traditional

defintion, although generally correct for process lenses, doesn't

necessarily apply to taking lenses, and isn't necessarily an

indicator of quality. But that's a whole bag of worms in itself.</p>

first off, thanks for the great replies! second, the page at zeiss

was very helpful, but some of it was, well, weak. in effect it said

that tha biogen got its name because it allows one to capture all

the life around oneself. ummmm, ok :) anyway, thanks for the

help!

 

oh, and if you know of any nifty lens-name-origins (like the dog),

please share! :)

 

have a good one all!

Somehow the point listed in my earlier post was lost. An example from one book: A lens designed by Emil von Hoegh (see the book 'A History of the Photographic lens' by Rudolf Kingslake for details) was built by C.P. Goerz and initially called a Double Anastigmat Goerz, later reduced to the acronym Dagor. It doesn't list specifically the Tessar origination, but these books are a good source for name origination. I can't copy the whole book here. The Tessar design appeared under 21 other trade names. See the book. Did I not make that clear? Guess not. Peoples names. Acronyms. Made up names.