The Leica 50mm APO-Summicron-M ASPH f/2.0 has been labeled “The best 50mm lens in the world”. I asked myself "how is it the best?" and when I came up short, I interviewed the designer of the lens himself, Mr. Peter Karbe.
The story of the ridiculously normal looking $8,250 Leica 50mm APO-Summicron-M ASPH f/2.0 lens for the Leica M cameras is the vision of a perfect lens, dreamt of for years by the master lens designer Peter Karbe.
He knew it was possible to make it, but unfortunately at the same time he also knew it would be impossible to demand from customers what it would cost.
In this article I will try to define what is so wonderful about it, and I will also give the backstory as to how this lens became reality.
The Peter Karbe Interview that almost didn't happen
When I visited the old Leica Camera AG factory in Solms in Germany in January 2013 I video-recorded a talk I had with legendary lens designer Peter Karbe. Unfortunately the sound was so bad (made on the D-Lux 6), I decided to do a written interview and not use the video. It was lying in the archive for a while.
When we met in April 2014 in the new canteen in Wetzlar, I told him this was the reason the interview hadn't been published.
"Well, I haven't been missing it", he replied with a big laugh and an attitude that overall show the nature of Peter Karbe. He reminds me of a shy school boy that avoids eye contact, but then when you ask about the airplane he is holding in his hand, he forgets his shyness and explains enthusiastically all about it.
The Leica M Monochrom "Henri" with the Leica 50mm APO-Summicron-M ASPH f/2.0 lens. They were both released in May 2012 in Berlin, and promoted a new level of resolution in details and sharpness.
Peter Karbe is Dope
What keeps him busy and enthusiastic in his office is funny enough also what can get him out of the office and speak enthusiastically and forget his shyness:
Lenses!
He obviously loves everything about lenses. I rememeber when he was doing a talk some years ago about the Noctilux f/0.95. This private person in front of 100 people, so enthusiastic about the details of the design that he can keep talking about it.
People I've talked with through the years just love Peter Karbe. That goes for high and low inside and outside Leica. Peter Karbe is dope!
(Definition of dope slang: "Awesome", "extremely cool").
One of the rare occasions where Peter Karbe was outside his office: October 2013 with hard-core fans in Singapore who also got him to sign his lenses. Photo by Ronald Yeoh.
I may not be a broadly known fact, but Peter Karbe finds 50mm lenses fascinating. He has made the outstanding 50mm Summilux-M ASPH f/1.4 that he admitted in fact is an APO design though it doesn't say on the lens. Him and his team decided to conquor the rules of everything and make a 50mm f/0.95 that is both lightstrong and a groundbreaking great lens wide open.
Peter Karbe finds the whole history of Leica 50mm lenses fascinating. Maybe one day we will have a talk about all of them, that is more than 20.
Leica 50mm APO-Summicron-M ASPH f/2.0 in silver was released in July 2016. (on the Leica M240 in silver).
Leica 50mm APO-Summicron-M ASPH f/2.0 in black (on a Leica M10-R in black).
Since the 50mm Noctilux f/1.2 with the asphere technologly of 1966, the development of lenses has moved towards higher performance through glass technology since 1975.
With addition of further glass technology, floating elements, APO, more compact focusing mechanisms inside the lenses, as well as new ways to mount the lenses, in recent years, we arrive at what is possible today. The 50mm APO-Summicron-M ASPH f/2.0.
The 50 APO was a difficult lens not only to produce, but also to grasp the concept of for the users. When the Leica 50mm APO-Summicron-M ASPH f/2.0 surfaced as prototypes in the stores, I used to meet people who told me, “If I should spend that much on a lens, I would rather get the Noctilux.”
Two weeks later I would talk to the same people and they would say, “I saw the lens in the store. It is fantastic! – I ordered one!”
I would ask, “What is it that is so fantastic?” and they would answer, “It’s fantastic!”
For me, I couldn't grasp what was fantastic. I suspect nobody really has been able to define what it is that is fantastic about this lens. So naturally, when I met Peter Karbe, that was my question.
Buy the new eBook
"The Freedom of Photographic Expression"
by Thorsten Overgaard
"The Freedom of
Photographic Expression" eBook for computer, Kindle and iPad
October 2016 (268 pages)
In this easy to read and apply eBook,
Thorsten Overgaard takes beginners and experienced photographers through the basics of controlling the light and the camera.
This book covers the technical side of photography from beginners level to semi-pro, features a number of photographs by Thorsten Overgaard and chapters on his philosophy on photography.
Only $148
Buy Now
Instant Delivery
"I've bought the new book - made a start reading it - it is really interesting.
I know it’s basic at the beginning but it isn't written in a patronizing way. I have been taking photographs for many years and have been lucky enough to be paid to take them for the last seven years; but it's always good to be taken back to the start"
P. S. (UK)
""Really enjoy your writing and teaching"
D. K. (USA)
"I love your insights on photography."
D.B. (USA)
★
★
★
★
★
★
Interview with Peter Karbe about the 50mm APO
Is this lens extremely sharp, or what is it that is so fantastic about it, Peter Karbe?
“Perhaps it is the sharpest lens in the world,” he smiles, “I don’t know! Sharpness is far from the only concept behind this lens.“
“This precision you always see in Leica lenses reflects in bokeh (out of focus). It is not always the lens design; but it is always a matter of high quality production.”
The Noctilux also requires high precision in production. You told that story a couple of years ago, how Leica Camera AG had to build new grinding machines with much smaller tolerances because the existing ones didn’t offer precision enough for a f/0.95 lens. This is an even smaller lens construction.
“In the 50mm APO-Summicron-M ASPH, the tolerance for all the elements is very tight. We had to adjust everything to an unheard standard to be extremely precise."
"It has a lot to do with precision in production to get the results we wanted. The most of the high price of this lens – $8,250 – is the result of the precision assembling. It’s not exotic glass or something; it’s the assembling that is very precise.“
If I should design my own perfect lens, I would look at the old 50mm Summicron Version II and start there. If you look at the skin details and textures of that lens, they are very alive. But I would wish for accurate colors, more tight light control and less overflow of light (especially in the details).
What considerations did you have when you had to design the 50 APO: What are the decisions you made when you designed the new APO?
“There are many aspects you have to think about when you start from scratch. The concept behind is a traditional Leica concept.”
“You are familiar with the old one. You know what you can expect from it. Now you have a new one and you will have to get familiar with a new one. You get to learn the aberrations … and in the 50 APO they are hard to find!“
(Definition of aberration, in optics: The failure of rays to converge at one focus because of limitations or defects in a lens or mirror. The word aberration comes from Latin, "to stray" and "wandering away").
“Some are pixel-peepers and try to look for all the aberrations, and they are hard to find in this one. Others look at the overall image and the colors.“
“The concept behind the 50 APO is to realize the best performance in small size.“
“What is best performance? You may ask,” he pauses and look at me as if this is a question he asked himself many times.
“Well, it is for example to maintain a highsharpness from infinity to close focus. The old Summicron is a Mandler design with a high performance. It’s a very good lens but there is a variation when you change distance. You have a performance-fall.“
“Also, when you stop down the aperture, you have a little unsharpness in the center of the field.“
When I look at the qualities in the 50mm Summilux f/1.4 with the pearl bokeh in black and white, accurate colors and high contrast, or the soft but detailed look of the old 50mm Summicron f/2.0 II, or the dreamy "controlled overflow of light" look of the 50mm Noctilux f/0.95 … I know you can’t make one lens that contain all these qualities at the same time.
So how do you select which ones to keep and which ones to focus on?
“It’s sharpness and all the aberrations are controlled. Is very technical how we control the aberrations. It is very much a Leica tradition in the programs we use, how we look at the aberrations and how we try to control them.”
“You will not find that in any other companies that does what we do. It is all typical Leica and is based on Barnack’s view and technology.”
“It’s not a formula or a computer algorithm. We have drawings of aberrations and then we look at them and think about which aberrations will result in which effect in the image. We control the aberrations directly with each image in mind.“
That makes sense. You most choose which to keep and which to remove. Some look cool others you want to get rid of?
"Yes, it is a choice with the image in mind. It is also very important to understand that we try to remove the aberrations within the system. Each lens element is chosen to deliver the performance by itself."
"In some other designs you will find strong lens elements, and when you combine them you will get a sharp lens. But each element will contribute strong aberrations. So traditionally other lens designers will try to reduce aberrations with other elements."
"At Leica we aim to reduce and minimize it within each element itself, with each surface and so forth. That is the concept and thinking behind everything we do."
"Minimize."
"Look at the M system. We aim to keep it compact and each element has a certain task and this need to be selected carefully. That is the general description and the reason we try so hard."
Max Berek wrote the textbook on optical design that everybody studies even today when they want to learn lens design, “Grundlagen der praktischen Optik” (published first time in 1930 by W. de Gruyter & co.).
Available as eBook or printed book.
So any other lens designer could do this, or do you have an extra secret?
”They need to understand why, and they need to know how to do that. That is our history of ideas at Leica.“
“We have a history of ideas.”
Leica basically did optics for 166 years, since the Optical Institute (renamed in 1869 to Ernst Leitz) was established in 1849?
“I’m talking about history for photographic lenses. The optics for Leica microscopes stretches a bit longer back. The history I represent started with Max Berek (1886-1949) when he designed the first 50mm f/3.5 lens for the Ur-Leica that Oskar Barnack made in 1911. That is our heritage. We learned from that.
"Everybody at Leica try to learn from that which others did before us,” he smiles. “It’s not learned at a university. We learned from them.”
“Our first lens designer was Max Berek. His concept was to reduce the aberration of each element, or of each lens surface. “
“Reduce the contribution of aberration from each surface, you could say. Control all aberrations … but that is too complicated to explain here, I think!” Peter laughs but looks like he would love to talk about it all week.
I am not so interested in more sharpness, I think. I’m trying to understand what you see as the main improvements in the new 50mm APO, besides the resolution and contrast?
“You don’t care about the sharpness? You mean the resolution!"
"You look at the light and the focus point with the much higher contrast. I know your pictures, and you work with depth of field. You need a certain level of sharpness."
"On axis the old Summicron II is perfect. It has color aberration, but on optical axis there is no doubt about it. On the optical axis (symmetry) the old and the new Summicron are very similar, so this was not a target for the APO. In fact there is not a very big difference on axis between them.”
Buy the new eBook
"Composition in Photography"
by Thorsten von Overgaard
Composition in Photography - The Photographer as Storyteller
This book will inspire your photographic eye and make you wonder about all the possibilities you can now see.
In this exciting new book Thorsten Overgaard expands and simplifies the subject of composition. It's elevated from geometric patterns to actual storytelling by practical use of space, rhythm, time, colors, emotions and intuition in your photography.
- The Basics of Composition.
-
Composition in the Third Dimension.
- Picture Stories.
- Accenturating with Light.
- Photograph as a Melody.
- Which lens are you?
- Fear of sharpness?.
- Vanishing Point.
- The most important
element of composition
- What is the unknown secret
why it is you mostly can't get
the Rule of Thirds to work?
- How does a camera see
differently than the eye?
- What does quantum physics and
photography have in common?
- What's the greatest adventure you can
set out on in photography these days?
- A Sense of Geometry.
Only $398.00. Order now. Instant delivery.
864 pages. 550 Illustrations.
"It’s your best work so far"
"I’m being gently led"
" I love this book!!!"
"The book is incredible"'
"It’s like therapy for the human spirit."
"Beautiful and inspiring"
"Full of practical advice
and shared experience"
'I love how hands-on and
laid back Thorsten's witting style is"
If I have a photo with a soft lens and increase the contrast in Lightroom, I increase the contrast in the picture overall. You are talking about only high contrast where the focus is.
“Yes!” Peter points a finger in the air and I feel like the student who finally got it, “the contrast has to fall off very fast in terms of depth of field. That’s it. That is the idea – and the ideal. The fall off has to be very fast!”
“You point the lens and shoot, and where the focal plane is, the contrast should be high. The front and behind should fall off very fast. That is the difference between the older Summicron lenses and the APO-Summicron. Not in terms of sharpness but in terms of contrast behavior.“
Apply
code "UPDATE113" on checkout to get this complete version 11.3 update.
$298.00
Updates all previous Surival Kit versions since 2009.
Buy the complete new
Lightroom Survival Kit 11.3
The Legendary Tutorial for Photographers
Brand-new JUNE 2022-version.
Now with brand-new 4+ hours of video tutorials.
New sections on compostition and storytelling.
How to edit color photos.
How to edit black & white photos. How to do keywords logical and easy.
The most successful photo editing kit ever
Photographer Thorsten Overgaard first released the Lightroom Survival Kit in 2009 and have honed it with new and fresh updates. This Version 11 is the most radical updated and renewed version ever, four years in the making.
Professional workflow experience made simple, logical and easy to use.
Master editor makes it simple to understand
The Survival Kit is unique and one-of-a-kind being made for photographers for photographers. When someone understands their subject, they can explain it so it is easy to understand. The hallmark of Thorsten Overgaard is to make expert knowledge shown and told in a way so anyone can apply it.
Hands-on advice that works
With a 450 pages workbook and 4+ hours of video, every element of digital photography is touched on, in handy chapters and pre-flight checklists. Editing of color vs black and white photos, keywording, cropping of images, fine-tuning of tones, color balance and color control, export of originals, printing, archiving and backup, and much more.
Comes with the Overgaard Leica Presets (Value $48)
The Lightroom Survival Kit comes with Thorsten Overgaard's special-made Lightroom Presets for all digital cameras and for Leica digital cameras.
Understand all from camera to the final print
Chapters in this version goes over the background for High Dynamic Range (HDR), digital raw files and how to set up a professional photography workflow, from calibrating the screen to editing in Lightroom, and to making a final print. And more ...
10+ years experience in one package
No need to spend years figuring out the smartest way to do things when you can tap into the best way of doing things right here. The workflow of Thorsten Overgaard as been refined through years of field work with more than a thousand workshop attendees.
This method of workflow now used by thousands
The Survival Kit has been taught to thousands in workshops and in this Survival Kit. What does it do? It make you enjoy taking and making photos, and it increases your production considerabely. Most important of all, it'll give you back ownership of your files (which you will understand why is so important, once you have bought the Survival Kit and started applying its methods).
"Thorsten's methodology is perhaps not what hardware-, software- and cloud-companies want us to do, but as a former IT engineer I can only acknowledge his views about preserving our digital heritage. This workflow explained is for me the best I have ever seen".
★★★★★
Video tutorials, image files, presets, checklists, definitions, tutorials of Lightroom, that boils down years of experience to a workflow you can implement in less than one day.
I like the 90mm APO-Summicron-M ASPH f/2.0 that seem to have so much more horsepower that it looks so natural and easy. As if the lens doesn’t even have to try to get the colors, details and feeling of surface or skin texture right and natural. It just gets it all effortless. Is there a relation between the 50mm APO (designed by Peter Karbe) and the 90mm APO (deigned by Lothar Kölsch) in the way they work?
(Peter Karbe doesn't really answer the similarities, but the 90mm APO-Summicron-M ASPH f/2.0 is known for being a new generation of lens design from 1998. The lens doesn't change quality from wide open a f/2.0 to f/16.)
“Due to the high-performance of the 50mm APO, the contrast – the smooth focus contrast … mmm“, Peter Karbe takes a deep breath before he continues to explain: ”Okay, the contrast has to go up towards focus and fall off behind focus.”
“From infinity to the focus point the contrast becomes better and better, and then it falls off after the focus point. We don’t talk about a maximum contrast or if it is 92% or 95% or 85%. That is not the big issue.“
“The big issue is how the contrast falls off out of focus. It has to fall off fast, ideally.”
Peter Karbe draws a curve in the air like a small hilltop: “This is the contrast behavior of the old Summicron, and this” – he draws a pyramid in the air with his finger – “is the new APO-Summicron.”
He laughs, “Its exaggerated” and makes the gestures in the air again, “but that is the principle!”
I look at a lens how it treats light and the look I get. Does the 50mm APO get me a magic look?
“Technically speaking, my interpretation of a good picture is: You get closer and you see more.”
Wow, that is well said!
It’s interesting, because I used the APO for a day at Cambridge University some time back. I didn’t think much of the pictures and had them lying around on the hard drive for some months. Then when I finally confronted them to see what I could make out of it, I noticed there was nothing added. They were very natural or neutral: They had a pleasant look, but no special look like the 50mm Summilux or 50mm Noctilux has.
A good microphone doesn’t add, remove or change anything. It just records what is. I saw the 50mm APO like that after I had looked at my pictures again. It doesn’t have a fingerprint you can recognize; it is almost like there is no lens.
“In my opinion the 50mm APO-Summicron-M ASPH f/2.0 is a new interpretation of no light photography. It has nothing to do with available light or low light. You have structures like black leather with structures inside,” Peter Karbe says and point at the black leather sofa in the reception at the Leica Camera AG reception.
“Let’s compare it to sailing,” he adds: “If there is much wind everybody can sail. If there is not much wind, it is hard to sail.
“It’s the same with low light. You don’t have so much light so the contrast is low. So you need a lens that sees structure and details.”
Inside the room of Ernst's daughter in the girls quarter at Cambridge University. It actually is more a small apartment than a room, with a separate bedroom. Leica M Monochrom with Leica 50mm APO-Summicron-M ASPH f/2.0
“It’s not available light,” Peter Karbe pauses, “but low light photography.”
“If you have to do a comparison between lenses and see which is a good lens and which is a weak lens, it is best to do it in low light.”
“If you don’t have so much light you need to collect each photon!” Peter Karbe laughs and I can sort of imagine him hunting photons in the air with a net, as if it was summer birds, “and the better the lens is to perform, to focus, the slower you can go down with the light.”
“Reflections and suppression of reflections is also part of that. That’s one aspect of perfection I think.”
“If there is sunlight you have high contrast and many structures with high contrast, so it’s easy to take a picture.“
With that we ended off. I found it intersting how little I know about lens design, and how technical Peter Karbes understanding of things must be. Yet we managed to talk about the same with different language.
I hope this interview clarifies some of the things people have been asking me about.
(Definition: photons are the fundamental particle of light and have zero mass. The word comes from Greek 'light'.)
It's a humorous understatement to call this
new eBook by Thorsten Overgaard for "A Little Book on Photography".
It's a grand book, a history lesson, life experience, a biography and poetry book and brilliant photo book!
All in one beautiful package of 180 pages
to fire you up and get you to love
photography ... unconditionally!
"A Little Book on Photography" eBook for computer, Kindle and iPad.
New release March 2017.
Intro price only $47- 180 pages.
This extension course if made for you! It can be done at home and travel at your own pace. I have taught workshops for years and the Overgaard New Inspiration Extension Course is my experience compressed to a package of training, articles, drills, assignments and video tutorials that will inspire you and take your photography to the next level! For a limited time my course includes something you cannot get anywhere or anytime else:
A portfolio-review by Thorsten Overgaard.
"The Overgaard
New Inspiration
Extension Course" For computer and iPad. 181 p eBook.
Only $798
Order now - Instant delivery.
Special editions of the Leica 50mm APO
LeicaRumors.com was first to break the news of an upcoming silver edition of the Leica 50mm APO-Summicron-M ASPH f/2.0. Not as a limited, special edition, but as a new product available from any Leica Store and any Leica dealer from JUly 19, 2016.
From July 2016 the Leica 50mm APO-Summicron-M ASPH is also available in silver.
The red Leica 50mm APO-Summicron-M ASPH f/2.0 there exist - most likely - only one of. That one belongs to Dr. Andreas Kaufmann, the owner of Leica Camera AG. It was made for him as a birthday present and has the serial number 0000001.
Another limited edition is this black Leica 50mm APO-Summicron-M ASPH f/2.0 with red feet scale that Hari Subramanyam got Leica Camera to make for him in 2015.
The 50mm Noctilux or the 50mm APO-Summicron?
A perhaps relevant question I get again and again, is "Do you prefer the Noctilux or the 50mm APO?"
Many know my love and admiration for the Leica 50mm Noctilux-M ASPH f/0.95 that I have had mounted on the camera almost exclusively for the last 2-3 years in sunshine and rain.
In 2014 I decided to force myself to use the Leica 50mm APO-Summicron-M ASPH f/2.0 almost exclusively on the Leica M 240. It was obvious to me that if I had to understand this lens, I had to use it a lot. There is so many reasons - aberrations as Peter Karbe would call them - not to use the 50mm Summicron from 1964. Yet that was what I had done from 2009 to 2012. First out of need and curiosity because I had the lens when I got the Leica M9. Later I just couldn't live without it.
Despite the old Summicron's lack of ability to manage colors when shot against the light, to name one clear and strong aberration - I managed to make images in both black and white that was clearly detailed and sharp, contrasty and - given not too difficult light conditions - created great color photographs.
The concept "perfect 50mm lens" has really bugged me. What's going to happen to my images when I use a perfect lens? That is what the 50mm APO-Summicron-M ASPH f/2.0 was promoted as, and I am sure Leica Camera AG have been regretting this marketing strategy a few times during the period where the new lens was first delayed, then recalled, not to mention the lenses people have sent back for service because they had dropped them or bumped into something so they went out of adjustment.
I think the conclusion is that no such perfect lens exists. You cannot buy yourself into "perfect".
Perfect is something a lens turns into when you use it. You add the perfection, so to say. The 50mm Summicron from 1964 turned out to be a perfect lens for me. Not that I didn't notice when it didn't perform as I would want, but perfect in the sense that is was my lens and I have made a lot of photographs with it that worked exactly as I wanted them to. Exactly as Peter Karbe said, I knew the lens and knew what to expect and how to make it perform.
Using a lens will always be an interrelation between the technology and me as user. When I got used to the 50mm Noctilux-M ASPH f/0.95 I knew what to expect and how one or the other scenario would look. That interrelation result in that I see and make the type of photographs that the 50mm Noctilux is good at.
I like this look at lot: It looks like a classic lens, yet the lens is able to control a massive amount of light breaking through from above, and at the same time display a lot of details and tones in the shadows. And it maintains a strong contrast.Classic meets new technology. Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0.
After a few months I decided to let my hearth decide which lens to use. I wouldn't force myself to use the 50mm APO-Summicron; I would pick the lens that I really wanted to use that day or for the assignment.
Mostly I would pick the Noctilux. It was for me the easy one, the relaiable one.
Not very different than deciding which car to drive today. You pick the one that is the most fun driving. Not necessarily the one with the best fuel economy or the most expensive one.
Just the one you feel like using.
What I really think of the
Leica 50mm APO-Summicron-M ASPH f/2.0
There is something about using the Leica 50mm APO-Summicron-M ASPH f/2.0 that is not very satisfying when I use it. It doesn't perform in a way that makes me happy.
This lens keeps under-performing what I somehow expect when I am out and about photographing. Then, when I look at the pictures after a while, I am struck and surprised how well it performs photographs that are classic looking, simple, relaxed ... yet perfect.
I think the term "perfect" make me expect something visible awesome, something in the order of a miracle. I also find myself worrying if the lens bumped into something that might misplace the elements. Something that would make the lens less "perfect".
What makes it perfect, if anything, is that it doesn't show any visible speciality. Other lenses have their fingerprints and a look. The 50mm APO-Summicron-M ASPH f/2.0 simply don't have anything other than that it got it all. It didn't miss a beat, it recorded the light and all details.
It recorded with clarity, clean colors, scary realistic details. It all looks natural. Add to that an interesting ability to see in the dark. Without the milky look the older Summicron lens has when faced with lots of light behind the subject.
In an age where so much software and so much photographic equipment is based on fluffy features that will do this and that ... meeting a piece of high tech that simply doesn't add anything. That's the miracle!
The most clear and true colors of any Leica lens
There is one case where I pick the 50mm APO-Summicron over the 50mm Noctilux, and that is when I want clean and clear colors. The photo of Terence Hines (above in the article) taught me that. The 50mm APO-Summicron has extremely lively and accurate colors.
Then again. I have done a few photo sessions where I have used the Noctilux and the APO-Summicron so as to try to compare them.
It goes like this: I trust the Noctilux to make me my images, but I suspect that the 50mm APO would capture it more real and clean.
I did a series of images recently where I made sure to have both lenses (and I used two cameras). I ended up choosing a Noctilux photo as the final one (for a frontpage). For the untrained eye (or perhaps anybody who didn't know it was two lenses), the differences wouldn't be obvious. What the Noctilux photo had - and usually has - was that feel I wanted. It just had a better atmosphere and emotion.
The 50mm APO-Summicron-M ASPH f/2.0 often has the look of a medium format when you pixelpeep the pictures. You blow them up to 100% size and the details are quite amazing. However, in my opinion, that is not as relevant for as the overall emotion and message of the photograph.
Darkness is probably where I have used the lens the least, but the few times I have used it in darkness, I have realized that it actually see details that other lenses don't.
The Leica 50mm Noctilux-M f/1.0 and f/0.95 used to be the ultimate low light lens. Fortunately I meet more and more people who realize it is not a low light lens, but a lens that sees light different. With a ND-filter on the Noctilux to neutrally reduce the amount of light it becomes a very exotic and rare tool even in strong sunshine. The way it deals with light is what makes it special. Not that it works in the dark. It's a nice feature, but it's not the key feature. With higher ISO-speeds the amount of light becomes less important, but the way it handles light will always be relevant.
The same goes for the 50mm APO-Summicron. It seems as if Peter Karbe and his team actually found a way to "use every photon". It has some very intersting and surprising features in low light and shadows.
As we will be getting new sensors in future cameras that will be able to go into even higher ISO range, the Leica 50mm APO-Summicron-M ASPH f/2.0 will become an even more intersting and valuable tool where there is - as Peter Karbe says it - no light.
There is no physical or electronic connection between the f-stop on a Leica M lens and the Leica M camera; which means that there is no recording of the f-stop used.
When you anyways can see an f-stop in Lightroom it is because it is calculated based on what the small eye on the top front of the Leica M body perceive to be the light condition, compared to how much light hits the sensor.
It is very often quite accurate. Though when you use a ND-filter that reduces the light with for example 2 stops, a f/2.0 lens looks as it is either a f/4.0 lens or that the f/2.0 lens was stopped down two stops to f/4.0. So even that also usually is accurate in Lightroom (if you remember that you had an ND-filter on).
However, my experience with the 50mm APO-Summicron-M ASPH f/2.0 is that the "guessed" f-stop is often wrong. It will go to extremes as f/11 or f/16 when the lens is in fact f/2.0.
I cannot find any reasonable (or actually any at all) explanation for this and have asked Leica Camera AG. I haven't gotten an answer yet why this could be.
Noctilux and APO - "Similar or better performance"
When I had a talk with Peter Karbe in November 2015 about the lens design of the 28mm Sumilux lenses (for the M and the Q) and the 50mm APO and 50mm Noctilux, I had a burning question to ask him.
Given that the Leica 50mm APO and the Leica 50mm Noctilux both are subject to the same rigid assembling procedure, they should have some of the same qualities in terms of precision.
What I am referring to is that if you open up a lens design from f/2.0 to f/1.4 (doubling the amount of light coming through the lens), you increase the abbarations 16 times. And similer again 16 times when opening the lens further from f/1.4 to f/1.0.
This means that when a lens designer moves from a f/2.0 design to a f/1.0 design, he opens a bag of worms in that there are 32 times more things that he has to control.
(I forgot if the opening from f/1.0 to f/0.95 added a few more abbarations. It probably did, but let's stay with the 32 times abbaration for the sake ofunderstanding. It's a lot!)
Hong Kong November 2015. Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 @ f/2.0. 200 ISO at 1/1500 second.
The unique about the 50mm APO is the small size of the lens and the small size of the optical elements: Leica M lenses are already smaller than most other lenses existing. In 35mm photography the APO is an exrremely tiny lens. In the APO is each piece of optics is used to the very edge of the round glass, requiring the grinding of the lens elements to be extremely precise from edge to edge.
Further, in assembling so small pieces, the tolerances are obvious smaller than for a much larger lens.
A 50mm Leica R lens is som much bigger than the 50mm APO that a 1/1000th milliemeter equals a 1/3000th milliemeter in the more compact design. Something like that.
That's why Peter Karbe previously told me that the high price of the 50 APO was mainly due to assembly costs.
The Noxtilux is much larger than the APO, but the lens design of a 0.95 lens require 32 times more precision than a 50mm APO.
My point is simply that if a lens design is 32 times "harder" to make, and it actually works that well, then that precision wide open at f/0.95 should result in similar extreme precision when stopped down to say f/2.0.
Following this logics, my qestion to Peter Karbe was a very simple and innocent one:
If the Noctilux requires 32 times more precision in grinding and assembling and also have (the luxory of) larger glass, then wouldn't it be able to handle light and colors just as well at f/2.0 as the APO-Summircon at f/2.0?
Peter Karbe: "Yes, at f/2.0 the Noctilux has same or better performance."
Now, this is something I have tested a few times in the past , but never formally: I don't do test benches, MTF charts and all that. It takes an effort even to use a tripod for me. I don't use one when I take photographs, so why would I suddenly use one to test something?
In other workds, turn to somebody else for scientific tests and comparisons. I just compare things the way I would use it and to understand how to use it better.
But I've been curious about the "perfection" of the 50mm APO compared to the f/0.95 Noctilux. I've made a few portrait sessions where I used the Noctilux at f/2.0 and the 50mm APO at f/2.0 and compared the results.
But what happened then is what happens mostly in life: I decide to use the Noctilux wide open at f/0.95 because that is what it does best and what I like the best about it. I've never asked myself how the Noctilux perform at f/16 becuase I never saw any reason to use it at f/16. But I know a lot about what it does at f/0.95, and how to get it to do that.
What's the point in having f/0.95 if you don't use it? If I "just" want f/2.0 then why would I spend the money on a f/0.95 and carry that heavier lens around?
It's very logical. If you have fallen for the f/0.95 Noctilux, there is nothing like it.
Which my "experiments" with the two lenses also confirmed. When I compared portarits at f/0.95 made with the Noctilux at f/0.95 to portaits made with the Leica 50mm APO at f/2.0, the APO wins on maximum image detail and color saturation.
But the Noctilux still won on the best portrait. The photogrpah I selected was the Noctilux one, not the more "perfect" 50mm APO. Because what I was looking for was not maximum image detail and color saturation but that unique dreamy look.
I all leads to the question: "Should I get the Noctilux or the 50mm APO?" and more recent, "Does it make sense to have both the 50mm APO and the 50mm Noctilux f/0.95..?"
Both you and I know what you would like the answer to bee:
"Yes sure. Get both!"
But in light of the above it doesn't make sense to have the Leica 50mm APO to obtain maximum image detail and color saturation ... if you are willing to carry a Noctilux and stop it down to f/2.0 whenever you want that "50mm APO look".
I am not going to perform experiments and comparisons for you so you can study them and see if the theory is right. So, if you like, take that as an excuse to get both and do some scientific comparisons yourself.
I didn't ask Peter Karbe this question to dis-encourage you to get both lenses. They are both beautiful lenses that represent the optimum of lens design and photography technology. That's another reason to get both.
I asked to understand the lenses better. For me it put things in perspective and actually made me more happy with my Leica 50mm APO than before. I've been considering getting rid of it because I didn't understand it. Now I understand more, so I like it more.
One of the things that has become obvious with the Leica SL 601 that was released in November 2015 is that the Leica 50mm APO performs extremely well on it. Not only does it sit very well on the camera and gives the camera a great balance. It's also very easy to focus on the Leica SL without having to enlarge the image in the EVF.
But the photographs the APO makes on the Leica SL is simply in a class for them self.
The maximum image detail and color saturation of the 50mm APO is showing off bright and clear on the Leica SL 610 images.
And what's intersting is that the Noctilux, 35mm and 28mm and all other lenses sort of looks the same on the Leica SL as they do on the Leica M 240. Only the 50mm APO stands out so clearly better that it makes me wonder why.
Leica 50mm APO look at different apertures
Here is a series of images made with the Leica 50mm APO-Summicron-M ASPH atall the stops from f/2.0 to f/16. I have made a similar series of the Leica 50mm Noctilux-M ASPH f/0.95 in the "Noctilux - King of the Night" article if you want to compare.
Aperture f/2.0: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/2.0. 400 ISO.
Aperture f/2.8: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/2.8. 400 ISO.
Aperture f/4.0: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/4.0 at f/2.0. 400 ISO.
Aperture f/5.6: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/5.6. 400 ISO.
Aperture f/8: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/8.0 at f/8. 400 ISO.
Aperture f/11: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/11. 400 ISO.
Aperture f/16: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/16. 400 ISO.
The Leica 50mm APO-Summicron aperture comparison
in black and white vs. color
Aperture f/2.0: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/2.0. 400 ISO
Aperture f/2.8: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/2.8. 400 ISO
Aperture f/4.0: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/4.0. 400 ISO
Aperture f/5.6: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/5.6. 400 ISO
Aperture f/8: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/8. 400 ISO
Aperture f/11: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/11. 400 ISO
Aperture f/16: Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0 at f/16. 400 ISO
Purple fringing in Leica lenses
Some times there is a visible fringning wide open in the 50mm APO-Summicron. People often look at the purple fringing as an error that better lens design will have to deal with, but truth is it is not going to go away anytime soon. As long as we have sharp lenses and "sharp" detailed sensors, we will have fringing.
Purple fringing is more likely to appear towards the edges than the center of the lens. That is also why wide angle lenses may have more fringing "problems" than 50mm and tele lenses. Fringing increase from the center of the image towards its edges.
In my case I like to use the lenses at wide open aperture without stopping down, and I like to shoot against the light. This provoke purple fringing of the sort that is seen on high contrast edges.
In some lenses you will see fringing in micro details and that is a type of fringing I am less concerned about. Modern Leica lenses deal well with that, and the 50mm APO in particular. The Leica 90mm APO-Summicron also deals very well with fringing in micro details so it is almost non-existent under any conditions. In both cases it results in extreme lively micro details of skin and texture. If you zoom in on an image, you see it. If you look at the overall image you also see it, but then it simply appears as a very lively and crisp image with very precise colors. It's like high fidelity in music. All the small details make up the overall aesthetic. Without details it's still nice music, or a nice image, but with the details it's another level of aesthetic and enjoyment. You don't have to know about each accurate detail to percieve it.
50mm Noctilux f/0.95 vs 50mm APO purple fringing
In the Leica Noctilux f/0.95 purple fringing is very visible wide open at f/0.95 and up till around f/2.8 when you shoot very high contrast (as a white shirt against a dark suit) or subjects against backlight.
It is visible in the Leica 50mm APO from f/2.0 to f/2.8 but less than the Noctilux: It takes more extreme contrast to provoke the purple fringing in the APO. If you care to study the two lenses and the similar samples made in this article and in my Noctilux article, you will see that they deal with it very similarly.
Here is a 100% enlagment of an image:Leica 50mm Noctilux (left) at f/2.0 and the similar image with the Leica 50mm APO at f/2.0. The strong backlight here is not enough to create purple fringing in the 50mm APO. But that doesn't mean that it never has purple fringing. If you look close, you can see that my focus changed slightly between the two lenses; it's not as scientific as I would have hoped. But it aligns well with my experience with the two lenses: The Noctilux always has an issue with purple fringing wide open when shot against the light.
These two lenses are the two Leica M lenses that require - and are subject to - the most precise assembling at Leica Camera AG, and the are some of the few lenses that are only assembled at Leica Camera AG in Wetzlar (and not at the Leica Camera AG factory in Porto, Portugal).
It's easy. In when you work in Lightroom and go to Develop mode, there is Lens Correction in teh bottom of the right panels. You click on Colors in that and you get a panel to control Purple Fringing.
In most cases you can simply turn the ruler all the way to the right and get rid of all purple fringing. In a very few cases there will be other colors in the picture that gets affected. So check dresses and other things if they suddently lost a color channel. Mostly the only effect it has on the picture is that the purple fringing disappears completely.
It takes a little while for Lightroom to process the change. The way Lightroom work is that it reads the DNG/raw file, then the sidecar with changes. The progream uses the computers processor power to render the preview you look at. That's why when you zoom in on an image, it has purple fringing; but then half a second later it disappeared. Next time you look at the picture, it has purple fringing again ... but half a second later it's gone.
Removing purple fringing in Lightroom
In this 100% crop from a Noctilux f/0.95 wide open at f/0.95 and against a strong light source purple fringing becomes visible. And can be removed:
Purple fringing:
Gone:
The only difference betweenthe two images is that I moved Amount of Defringe from 0 to 20.
What is purple fringing?
Purple fringing is a failure of a lens to focus all three main colors (Red, Green and Blue) to the same convergence poin, also known as "chromatic aberration". But not all purple fringing can be attributed to chromatic aberration.
Colored fringing around highlights may also be caused by lens flare (burst of bright light).
Another cause of purple fringing is chromatic aberration in the very small microlenses used to collect more light for each pixel on a digital camera sensor; since these lenses are tuned to correctly focus Green light, the incorrect focusing of Red and Blue results in purple fringing around highlights.
On photographs taken using a digital sensor, very small highlights may frequently appear to have purple fringing where in fact the effect is because the highlight image is too small to stimulate all three color pixels
Chromatic aberration also affects black and white photography. Although there are no colors in the photograph, chromatic aberration will blur the image.
The longer focal length, the less purple fringing there traditionally is.
The more a lens is stopped down, the less purple fringing there is.
I bump into things, and some times I drop a camera on the floor. My lens shade on the Noctilux has been fixed and replaced several times and the filter tread on the lens has been replaced twice because the lens had been hit so hard the filter tread was bend and I couldn't screw an ND filter onto it.
Does that make me wonder if the glass in the lens has also been shifted? Of course! Several times I've had the idea that a lens had to go back to Leica Camera AG to get adjusted completely. I look at the images and I wonder if the fringing is because the optics inside has been misplaced.
But when I get my hands on a similar lens and have had opportunity to test two lenses against each other, again and again I have beena ble to establish that the lens was working perfectly fine.
I'm just mentioning this as you might suspect your purple fringing to be caused by inaccurate mounting of the glass. And if so, stop worrying about it.
Purple fringing in monchrome pictures
I most often use the JPG Fine from the Leica M 240 (and Leica M9) as my monochrome iamge. I set the camrea so it does DNG and JPG Fine at the same time, and then I set the JPG Fine to black and white.
A sensor, and also a monochrom sensor, sees colors (Red, Green and Blue) and of course fringing. I recently edited some pictures where I used both the color DNG and the JPG Fine b&w but realized I had to re-edit this one. In this crop of the image you can see the problem and how I solved it:
Original DNG without correction:
Original DNG corrected for purple fringing:
It's evident that the high contrast from the backlight, with a dark silhouette in front of it, out of focus, will create purple fringing. f/.095 Noctilux at f/0.95, 400 ISO 1/60.
Here the same image to the left is corrected in Lightroom.
Original JPG Fine black & white from camera:
New black and white made from corrected DNG:
The JPG Fine monochrom image has strong signs of the purple fringing that was translated to monochrom in the camera while making the JPG Fine.
Here is the new black & white image made in Lightroom by using the corrected DNG color image as the basis. I simply change it to black & white in Lightroom and then edit it to the tonality and contrast I want.
When to watch out for purple fringing
Strong sunlight or strong light from a lamp is a condition that will very often result in purple fringing. The strong light hits an edge of something and you get purple fringing.
If you shoot against the light, purple fringing is likely to occur on any high contrast edges.
But the light condition that might surprise you the most is low light photography agains a low light source. It's typically that you shoot against a window or opening in a dark room and with dull light from behind. You won't recognize this as sunshine. Far from, because the whole scenery is so soft lit it's almost dark. But this is where you will realy get intro purple fringing trouble.
This is also the type of light that is so soft and dark that most people don't see how beautiful it will be when the camera compensate for the darkness and make it daylight. But with the advantage that the softness stays and there are no hard shadows on faces, the small reflections that are invisible to the eye in so low light sparkles in the image. If you photograph in the twilight or "blue hour" (which is the 30-60 minutes) after the sun disappear in the horizon, that's the type of dark soft light.
The sample above looks as a flood of light but is shot at 400 ISO f/0.95 at 1/60 second. That's how little light there is. But relatively there is a flood of light coming in from the window behind.
Lulu working on a plan. Hollywood 2015. Leica M 240 with Leica 50mm APO-Summicron-M ASPH f/2.0.
A side note on ND filters in soft backlight
As a side note, this is also the type of light where use of filters become a problem. Clear filters will possibly create some reflections and softness of the image. Either visible or not. Grey filters (or ND filters; Neutral Density filters) will create softness due to their dark surface that relects internal like a mirror. And the variable ND filters with two dark glass surfaces mounted as a sandwich will for sure create softness in an image made in soft light with a light source behind.
You wouldn't nomrally have an ND filter on to recude the light in such conditions, but if you use a variable ND filter you might actually keep it on and set it to just a 1/3 stop reduction of light. As such, the ND effect will not cause any problem for the exposure (being just 1/3 stop), but the two layers of dark glass will.
Loss of contrast with variable ND filters against "strong" light source in low light:
With the B+W Variable ND filter
f/0.95 at 800 ISO at 1/90 second.
Without the B+W Variable ND filter
f/0.95 at 800 ISO at 1/45 second.
Leica 50mm APO: "Effortless"
When I look back at pcitures I did with the Leica 50mm APO over the last few years, what strikes me is one word:
Effortless.
The Leica 50mm APO-Summicron-M ASPH f/2.0 pictures has a natural look that is classic, yet very modern in technical quality. There is no evident added contrast or added sharpness. It's just a natural balance.
The backstory of the Leica 50mm APO-Summicron lens
Peter Karbe knew for years it was possible to make the perfect 50mm lens, but unfortunately at the same time he also knew it would be impossible to demand from customers what it would cost.
I frankly don't know what happened that changed things. But let me guess: Inside the old Leica Camera AG factory building in Solms, built in a less fortunate period of the 100 year era of the Leica camera brand was a crazy CEO - in a sort of good way - Mr Steven Lee (2006-2007) who had grown a lens-designer-crush on the shy and genius Peter Karbe.
Also inside that pathetic 1980-style factory building was the visionary Andres Kaufmann who had bought his way into the Leica factory. He bought a Leica pocket camera a few years before and liked it so much he lusted for more.
In retrospect some could compare Andreas Kaufmann to Steve Jobs. He took over a trainwreck and turned it into thriving financial success.
To complete the picture, Leica at this point in time - beside working on not dying - had launched an expensive R&D program to develop the Leica medium-format camera Leica S. A project so daring it was nothing less than to live or die in the attempt.
What exactly happened inside the factory that made them give Peter Karbe the green light to make the dream lens is up to anyone to speculate about. A deciding factor could be that all over the world enthusiastic people were on waiting lists for Leica lenses. The exotic Leica lenses such as the $5,000 Leica 35mm Summilux-M ASPH f/1.4, the $4,000 Leica 90mm APO-Summicron-M ASPH f/2.0 (two years waiting list), the $10,500 Leica 50mm Noctilux-M ASPH f/0.95 (one year waiting list) ... the list goes on.
Leica Camera AG was a factory where the employees would spend more time answering calls about "When can I get more lenses?" with "We don't know!" than counting the nonexistent stock. The worlds most expensive lenses for 35mm cameras couldn't be produced fast enough to supply demand.
In light of this if you are a true adventurer, of course a $8,000 lens can be marketed and sold.
Yes, that pretty much sums up what anybody in a business school should know about this example of decision-making and market analysis of supply and demand.
I don't like to talk about left and right brain, but in this context it might help to shed some light over what Leica is, and how it became Leica.
The beginning of Leica was when a genius, Oskar Barnack, trollyed around in Wetzlar in 1910-1911 and somehow combined his fasination for motion picture with an idea of putting motion picture film inside a small, portable metal box with a lens attached. This became the first Leica camera, the Ur-Leica.
The owner of Leica back then, the Leitz family, had made microscopes for almost a lifetime and had lost a lot after World War I; the whole Russian market to be exact. School kids would collect their dads paycheck at noon in the factory in Wetzlar, then run as fast as they could to the bakery to buy bread before the inflation caught up with them. It was hard times.
Nevertheless, at a point where things had looked realy awfull for a number of years, the Leitz family decided to put this new technology into production and make a batch of 1,000 cameras to be launched in 1925.
Despite a lot of wise peoples advice that such a small camera could never work, the Leitz family and their dedicated staff made it into the worlds dominating camera for the next 35-40 years.
Without this reckless decision made at the worst possible time, Leica wouldn't have become Leica.
One of many highlights in the period after the introduction of the Leica was the Leica 50mm Noctilux-M f/1.2 that was an impossible lens made into reality in the 1960's.
Oh yes, and the Leica S as well. A complete new camera system developed from scratch, aimed at a professional market it has even today hardly started to penetrate. But so popular amongst well-off and wealthy photo-enthusiasts, that segment alone has made it into a financial success.
Something interesting happens when you apply German precision engineering to stupid dreams: They work and become state of the art tools. The stuff people dream of because nobody else does such stuff in a world where most braindamage in research and development departments is occupied with how to make more stuff for less money.
The impossible dream lens
The 50mm APO-Summicron-M ASPH f/2.0 lens follows this pattern of unlikely dreams made into reality by reckless decisions from the minds of dreamers. Ideas realized at times where any banker with a sound mind would have required the key to the factory and spent every hour awake trying to split the company up in smaller pieces to liquidate it.
In contrast to this clearly right-brain management of the brand is the left-brain: The defensive and cautious products aimed at pleasing what is presumed to be the market that everybody is fighting to get a fair share of.
It is unlikely Leica would have survived without both the left-brain and the right-brain, but what should be noted is that without the reckless decisions about launching crazy products into the market, the Leica brand wouldn't be so special.
Steve Jobs said in 2010 that Apple was always about how to make the best possible product for the end-user, and it always would be. This is a strategy that led Apple to becoming the most valuable company in the world.
It's not a bad idea to make the best possible products.
In all fairness, the left-brain products from Leica have supported the company well. The small cameras made with Panasonic have generated a lot of revenue in times where Leica Camera AG wouldn't have survived without it.
The binoculars are still an important part of the Leica Camera AG revenue.
The 100th year anniversary of the Leica camera in 2014 was an avalanche of left-brained decisions to make limited editions of almost everything in the catalog, with a brain-dead "100 Year" stamp on top.
If we take a short trip in the time machine to year 2050 and look back, then how many will rememeber the Leica with a "100 Year " stamp on the top plate?
That's right, very few! What we will be talking about will be the 50mm APO-Summicron-M ASPH f/2.0, the Leica 50mm Noctilux-M ASPH f/0.95, the Leica M Monochrom, the Leica M9 and possibly the Leica S family.
Those dream-toys are what made and still make the Leica brand.
In 2050 those products will still be traded on eBay, just like the 35 year old Leica Noctilux-M f/1.0 from 1980 is still traded at lossless prices if you bought the lens back then and sold it now.
In a few years, if not already, most of us will have forgotten the clumpsy introduction of the Leica 50mm APO-Summicron-M ASPH f/2.0. Let's recapture it while we still remember, and then forget about it:
The final stages of introducing the lens turned out to be painful for both CEO Alfred Schopf and the lens designer Peter Karbe, and a few others. For some very long months that must have felt like eternity, nobody was really happy to talk about when the lens would actually start to ship. The level of precision work assembling the new lens was on the edge of what even Leica Camera AG could manage.
To put things in perspective, the Leica Cine lenses are so demanding to produce that the people with the most steady hands have been moved over to that production line. They came from the Noctilux production, amongst other places.
Whatever the idea as to how the 50mm APO could be produced and assembled, and by who, Leica Camera AG had to make a few adjustments before they got the hang of it.
When the lens finally started shipping in small numbers, Leica Camera AG had to go through the embarassment of recalling some of the first lenses to investigate occasional flare problems that Lloyd Chambers at digiloyd.com had reported about. For a very long time nobody at Leica Camera AG couldt explain the reason for the occasional flare, even less find a solution for it.
Eventually they figured it out and got it right. Or they stopped wondering and went back to the original plan on how to make it right and followed it rigidly.
Now people are waiting happily as usual for this wonderful lens that doesn't look much different than others from the outside, except the accompanying price tag of $8,250.
Leica 50mm APO Definitions
APO
stands for "apochromatically corrected" lenses. In most lenses, optical design concentrates the focus of blue light and green light into a single plane, but red light falls slightly into another plane of focus. Red subjects, therefore, would be ever so slightly out of focus compared to blue and green subjects in the same frame. In APO lenses, the design and expense has been put in to making red light focus on the same plane as blue and green. Under a microscope you would see that all light subject is now in focus, creating a sharper image overall. Many manufacturers offer APO designs, but in most of these only the very center of the lens is APO corrected. Leica prides itself on making most of the frame APO corrected.
Before correction
APO lens
ASPH
… stands for "aspheric design".
Most lenses have a spherical design - that is, the radius
of curvature is constant. These are easy to manufacture by
grinding while "spinning" the glass. This design
however restricts the number of optical corrections that can
be made to the design to render the most realistic image possible.
ASPH lenses, however, involve usually 1 element that does
*not* have a constant radius of curvature. These elements
can be made by 1) expensive manual grinding, 2) molded plastic,
3) Leica's patented "press" process, where the element
is pressed into an aspherical ("non-spherical")
shape. This design allows the manufacturer to introduce corrections
into compact lens designs that weren't possible before. Practically,
the lens performs "better" (up to interpretation)
due to increased correction of the image, in a package not
significantly bigger than the spherical version.
ASPH is a method where the glass is pressed, and if you think about it for a little while, it means that you can make shapes that you can't possibly grind: With grinding you can make a curved shape. With pressing (ASPH) you can make the shape of circles in the water if that is what is required.
Normal speric lens (grinded)
ASPH (note the shape of the glass as result of pressing reather than grinding)
There
is another Aspherical lens manufacture technique: an uneven
coating layer is applied to a spherical lens. The coating
is thicker on the edges (or on the center, depending). Canon
"Lens Work II" calls these "simulated"
aspherical lenses. Simulated and Glass-Molded (GMo) asphericals
show up in non-L Canon lenses, while the L lenses have actual
ground aspheric elements.
Bokeh
the visual quality of the out-of-focus areas of a photographic image, especially as rendered by a particular lens : It's a matter of taste and usually photographers discuss a 'nice' or 'pleasant' bokeh (the out-of-focus area is always unsharp why the quality discussed is if one likes the way it renders or not by a particular lens).
ORIGIN from Japanese 'bo-ke' which mean 'fuzziness' or 'blur.'
Summicron
Refers to the maximum lens aperture - here f2.0 . There are many guesses how this name came about, a popular one being that the "summi" came from "summit" (summit means the highest point of a hill or mountain; the highest attainable level of achievement) while the "cron" came from "chroma" (ie. for colour). Not so: The name (Summi)cron was used because the lens used Crown glass for the first time, which Leitz bought from Chance Brothers in England. The first batch of lenses were named Summikron (Crown = Krone in Deutsch). The Summi(cron) is a development from the original Summar (the 50mm f2.0 lens anno 1933)
Mandler, Dr. Walter (1922 - 2005)
Legendary Leica lens designer. Read more in Leica History.
Otto Geier, supervisor of the Optics Department of Ernst Leitz Canada (on the right), with the legendary lens designer Dr. Walter Mandler.
Other resources for the Leica 50mm APO-Summicron-M ASPH f/2.0
Erwin Puts'few precise words on the precision and technical accomplishments the new 50mm implies:
"I cannot repeat it often enough, but high-quality imagery with a lens of small dimensions is very difficult to achieve. The 50mm APO-Summicron-M needed to have a front lens diameter of 39 mm (the normal filter size for Leica Summicron standard lenses). The new 50mm APO-Summicron-M has eight elements that have to be fitted in a small-sized mount and there is indeed hardly room for air in this mount. This is a second problem: when lens elements are packed as closely as in the 50mm APO-SummicroniM the potential for aberration correction is restricted. It is a triumph of optical and mechanical design" - Erwin Puts
See his Page 1 and Page 2 of his article on the 50mm APO.
Steve Huff also have reviewed the Leica 50mm APO-Summicron in his Part 1: "Technically, the best 50mm lens I have ever shot with. Period. End of Story. Done Deal. No contest. Really!" – Steve Huff.
Leica 50mm APO-Summicron-M ASPH f/2.0. Model 11141. Black $9,095.00. Buy from BH Photo / Amazon
Leica 50mm APO-Summicron-M ASPH f/2.0. Model 11142. Silver $9,395.00 Buy from BH Photo / Amazon
Leica 50mm APO-Summicron-M ASPH f/2.0 Red anodized limited edition 100 pcs (2016). Was $8,795.00 as new.
Leica 50mm APO-Summicron Black Chrome in barrel design as the Summicron 50mm f/2 (II) from 1956. Limited to 700 pieces worldwide. Model 11 811. Was $8,995.00 as new, generally $15,000+ second hand.
Leica 50mm APO-Summicron-M ASPH f/2.0 LHSA in barrel design as the Summicron 50mm f/2 (II) from 1956. Limited edition 200 pcs (2018). Chrome model 11187. Was $9,595.00 as new, generally $25,000+ second hand.
Leica 50mm APO-Summicron-M ASPH f/2.0 LHSAin barrel design as the Summicron 50mm f/2 (II) from 1956. Limited edition 300 pcs (2018).
Black Laquor Paint model 11186. Was $9,595.00 as new, generally $20,000+ second hand.
Thorsten von Overgaard is a Danish-American multiple award-winning photographer, known for his writings about photography and Leica cameras. He travels to more than 25 countries a year, photographing and teaching workshops to photographers. Some photos are available as signed editions via galleries or online. For specific photography needs, contact Thorsten Overgaard via email.
You can follow Thorsten Overgaard at his television channel magicoflight.tv.
I am in constant orbit teaching
Leica and photography workshops.
Most people prefer to explore a
new place when doing my workshop.
30% of my students are women.
35% of my students dotwo or more workshops.
95% are Leica users.
Age range is from 15 to 87 years
with the majority in the 30-55 range.
Skill level ranges from two weeks
to a lifetime of experience.
97% use a digital camera.
100% of my workshop graduates photograph more after a workshop.
East Berlin. 
Outdoor Ping-Pong. 
