If you could ask Peter Karbe one question...

[Wonzo]

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I would ask him one question:  If he had to decide, which three Leica lenses would he keep forever and why?

[elmars]

vor 11 Stunden schrieb adan:

The three questions I've always wanted to ask Peter Karbe (pick one as desired):

1) Is it appropriate to design lenses with a concave rear surface (e.g. 35mm f/1.4 Summilux-M-ASPH, 75 APO-Summicron-M-ASPH) for use on digital cameras with a highly-reflective imaging surface (i.e. sensor glass, instead of film gelatin)? Does that not risk producing reflected and semi-focused flare (sensor > rear-element > sensor) by "re-imaging" the image on the sensor back onto the sensor, as would any concave "mirror" lens?

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I've had both those lenses produce "hot-spot" flares around bright objects against a dark background.

Studio example from the 75 ASMA on M9 - white chicken "reimaged" as a blurred hot-spot in the center.

2) Is it appropriate to design lenses with a rapid fall-off in focus either side of the image plane - IF those lenses are to be used with a "proxy" focusing system such as the M rangefinder, especially when used in rapidly-moving situations (such as journalism/documentary)?

Or would it be better to retain a little spherical aberration and "focus spread" to get "reasonably sharp" images either side of the focus plane, and smooth/extend the transition from sharp to blurry?

3) Equally, on a proxy-focus rangefinder system, with longer lenses (less DoF - 135, 90, 75, fast 50mm).

Is it not better to have a long focus-throw (~180°) for better finger-tip vernier precision, rather than a short-light-rapid (<110°) focus throw?

Adans posting is - like always - most valuable.

Question No. 1 seems very important to me, because sometimes I have flare on my pictures, that I could not explain yet.

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[Gelatino]

Will the MFD at 0,3m be a new norm for lenses to come, and are there some previous lenses that "could" be re issued with that new norm?

[pgk]

6 hours ago, laowai_ said:

I’d be curious to know if Leica is ever considering engineered materials for non-structural parts of the lenses (as opposed to all-metal constriction).

They used plastic in the construction of the 35mm Summicron v.4 which is why it can be very difficult to repair if this sustains damage. As far as I am aware they have not tried to do so with M lenses since.

[Steven]

4 hours ago, logan2z said:

I might change my previous submission to this one:   Can you show us some of your favorite photos you've shot recently?

(You know, the thing that all this crap is supposed to be about? 😁)

May I modify your question to "Can you tell us of some of your favorite photos you've recently shot?" This way, I think there are more chances to get an answer. 

[logan2z]

1 hour ago, Steven said:

May I modify your question to "Can you tell us of some of your favorite photos you've recently shot?" This way, I think there are more chances to get an answer. 

Sure.

[cboy]

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Karbe Q. What is an optical challenge do you seek to improve/ focus upon in M/SL lens development?

I remember asking him in a online forum discussion of how if the macro/dual range focus system in the Q can be implemented in others systems. Answer was yes. Not surprising as it was done before with 50mm cron DR. Few months later, lo and behold, out came the 35mm apo..lol 

Edited July 7, 2021 by cboy

[Steven]

3 hours ago, Gelatino said:

Will the MFD at 0,3m be a new norm for lenses to come, and are there some previous lenses that "could" be re issued with that new norm?

They are going to reissue the 50 Lux soon with the 30cm MFD. 

[evikne]

8 minutes ago, Steven said:

They are going to reissue the 50 Lux soon with the 30cm MFD. 

I'm really excited about this one!

[Steven]

Just now, evikne said:

I'm really excited about this one!

Don't tell you heard it from me 😜

[evikne]

21 minutes ago, Steven said:

They are going to reissue the 50 Lux soon with the 30cm MFD. 

Do you know anything more about this lens? (I'll not tell anyone that I heard it from you! 🤐 😄)

[Danner]

5 hours ago, Steven said:

May I modify your question to "Can you tell us of some of your favorite photos you've recently shot?" This way, I think there are more chances to get an answer. 

Here's a probable answer:

Oh yes, I took a picture of my cat sleeping on the couch, and a picture of a wrought iron fence at an angle that shows DoF awesome bokeh, and a picture I snuck of some strangers eating street food at a fair.

 

LOL

[darylgo]

2 hours ago, Steven said:

They are going to reissue the 50 Lux soon with the 30cm MFD. 

Reissue?  As in the same optical formula as the present asph?  

[pippy]

12 minutes ago, Danner said:

...Oh yes, I took a picture of my cat sleeping on the couch, and a picture of a wrought iron fence at an angle that shows DoF awesome bokeh, and a picture I snuck of some strangers eating street food at a fair...

Is he following me around?!?!?.....

Philip.

[pgk]

1 hour ago, pippy said:

Is he following me around?!?!?.....

Philip.

No me I think🤔.

I even have a copy of "The cat in photography" (by Sally Eauclaire) so there really no hope, even though the first image inside is by Edward Steichen and images it contains are by the likes of Muybridge, Rejlander, Friedlander, Imogen Cunningham, Weston and more.

Edited July 7, 2021 by pgk

[Martin B]

My question: why do newer Leica lenses in general have no IR focus mark - are they all corrected for infrared light that there is no focus shift in infrared? 

[otto.f]

The answer is clear: digital 🤩 bias. Seems more a hint than a question. 

[Jeff S]

16 hours ago, Wonzo said:

I would ask him one question:  If he had to decide, which three Leica lenses would he keep forever and why?

He’s already provided two (see my post/link earlier).  Last year it was the SL35 APO; now his ‘forever’ lens is the 35 M Summicron APO.  No surprise.  
 

He also talks about his personal photography/subjects in the linked interview.

Jeff

[FrozenInTime]

How about a tilt lens or two. 

The depth of field with a 35mm focal length is not enough to cover foreground to infinity, so much detail is lost or diffracted away in the attempt.

And a shift set - wide angles like the 21mm often benefit from some shift or crop to clear the foreground in architecture or cloudscapes.

In both cases any thoughts on simplified mechanisms that keep the lenses compact, robust and affordable.

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Hallo,

Look here: Leica M

[Guest]

20 hours ago, logan2z said:

I might change my previous submission to this one:   Can you show us some of your favorite photos you've shot recently?

(You know, the thing that all this crap is supposed to be about? 😁)

But why would you ask an optical engineer that? surely ask that question to a photographer?

Its like asking rachmaninov how many piano's has he built lately?

Edited July 7, 2021 by steve 1959