Peter Karbe lecture on new lenses at the Leitz Park opening

[AlanJW]

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Considering APS-C format what would be purpose of 50mm lens forTL/CL? There are already Summicron 23mm and Summilux 35mm TL lens which have FOV of 35mm and 50mm respectively on full frame.  Any deiidicated 50mm lens would be 75mm FOV, unless question is specifically with respect to short telephoto.

Good point.

[mmradman]

Perhaps this is the wrong forum for the question, but were there any lenses or updates mentioned for the M or the TL/CL? 

 

As long as conversation doesn't divert towards wrist watches nothing wrong querying about new lenses regardless of camera system.  

 

I think we are all keen to hear about new lenses and cameras.  If Leica wants to diversify away from optics it is their privilege but they would be well advised to keep it away from the current LUF. I have zero interest in Leica watch and about 1% interest in camera/lens special editions.  I would be grateful to a link of a presentation made by Herr Karbe where he talks about new lenses and optical developments.

[LD_50]

There is a Summilux 50 for SL. Very big and heavy but excellent. Are you suggesting a smaller version somehow? I'd be for that.

I own the Summilux 50 SL. I am not specifically suggesting any new TL/CL lenses, but was simply responding to a few posts regarding the new Summicrons being used on TL/CL.

 

If I were developing a TL/CL roadmap, I would focus on small size, not on duplicating the SL focal lengths and apertures.

[01af]

I would be grateful to a link of a presentation made by Herr Karbe where he talks about new lenses and optical developments.

 

In his lecture, Peter Karbe didn't mention any lenses that we don't already know about. The latest ones he was talking about were the Noctilux-M 75 mm Asph and the two upcoming 35 mm and 50 mm Summicron-SL lenses (due by the end of the year). No hints about any lenses planned further down the road.

 

He said that he doesn't design lenses anymore; the last one he was personally involved in was the Summicron-TL 23 mm Asph. He didn't give any hints as to why ... I suppose being the head of the growing optical design department he is busy doing administrative tasks and, maybe, implementing his future successor lens designers.

 

He explained, among other things, the concepts of light flux and relative size. Light flux basically is lens speed in relation to sensor size—for the same flux, the smaller sensor requires a faster lens. Relative size is the length of a lens' optical cell from the first to the last glass surface, divided by the image circle diameter.

 

He also reminded us of a book by Dr. Paul Wolff, "Groß- oder Kleinbild?" ("Large or small format?"), written in the late '30s, where the author discusses the merits of the then-new 35-mm format and how it compares to the established larger image formats—a discussion that is still current 80 years later, now involving 35-mm, APS-C, Four-Thirds, and other sensor formats.

 

And he said that modern lenses don't need to be stopped down for good performance. Stop down only when you actually need more depth-of-field! Actually, using a smaller image format would be the better solution when you need some DOF.

 

 

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Peter Karbe at Leitz Park. Wetzlar, June 2018.

[scott kirkpatrick]

Now here's a puzzle -- what color is that suit and that shirt?

 

In my earlier comment that several subsequent posters couldn't understand, yes, I think using the smaller and probably supersharp SL 50 Summicron on a CL as a medium telephoto with very fast AF, will make sense.  Of course, I will also use it on my SL.

[Guest VVJ]

For handheld usage a 700g lens on the CL body sounds rather front heavy to me... 

[scott kirkpatrick]

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 ....

 

He said that he doesn't design lenses anymore; the last one he was personally involved in was the Summicron-TL 23 mm Asph. He didn't give any hints as to why ... I suppose being the head of the growing optical design department he is busy doing administrative tasks and, maybe, implementing his future successor lens designers.

 

He explained, among other things, the concepts of light flux and relative size. Light flux basically is lens speed in relation to sensor size—for the same flux, the smaller sensor requires a faster lens. Relative size is the length of a lens' optical cell from the first to the last glass surface, divided by the image circle diameter.

 

 

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Peter Karbe at Leitz Park. Wetzlar, June 2018.

From the slides that David Farkas was kind enough (and quick enough) to post on Twitter, it appears that he covered some points that have been exposed before, but included new information about the 35 SL Summicron (and perhaps the 50?).  It would have been great to be there and able to ask a question over the wine afterwards.  Such as what does "light flux" tell you about the consequences of choices made in lens design.  (E. Puts mutters about light flux in his book.  I'll go look there.)

 

In an area that I know a little bit about, design of microprocessor chips, no one designs a processor by themselves any more.  The whole area is wrapped in design analysis and verification software that reduce the risk element in the very expensive manufacture required.  Once there was a mythology of the "tall thin designer" who understood the design process at each of its levels of abstraction.  I suspect that optical design of ultra high performance lenses has undergone a similar evolution from the days of Dr Berek managing aberration tradeoffs with paper and pencil calculations in his notebooks.  So it is no surprise that Peter Karbe manages a large team, but I would still like to know how he sets design objectives and what choices the team exposes.  And of course, we love to speculate about how other companies' design teams are involved, but i doubt that a glass of wine would be enough to get that information out...

Edited June 19, 2018 by scott kirkpatrick

[erudolph]

Scott, if you have the pdf version of the Leica Compendium, you’ll quickly find Puts’s remarks on geometric flux.

[BCMielke]

I wish I could find that pdf of the Leica Compendium.  Every time I go looking it seems to be gone.  

[Jeff S]

I wish I could find that pdf of the Leica Compendium. Every time I go looking it seems to be gone.

http://lmgtfy.com/?q=Puts+Leica+lens+compendium+pdf

 

Jeff