Huawei invited us to visit their partner Leica headquarters in Weltzar, Germany, to show us what the legendary camera maker is all about and to discuss how they managed their engineering collaboration to deliver the AI-powered triple-lens camera of the P20 Pro smartphone.
The tour started with an overview of the architectural concept behind Leica Camera AG’s head office. Architects Gruber Kleine-Kraneburg were inspired by camera parts’ shapes when they designed the administrative and manufacturing complex in Wetzlar.
The idea was to convey “tradition and modernity, quality and perfection” while “paying homage to the roots of Leica.” The recently rebuilt headquarters were officially opened in May 2014, for the 100th year anniversary of LEICA photography (video min).
After a brief history of Leica, presented by spokesperson Lukas Hollmann , we watched a video presenting the semi-manual manufacturing process for Leica highly praised top quality lenses .
The tour ended in some non-restricted areas of the factory, where the Q&A and the customer service teams operate. The visit closed with a 45 minutes conversation with Huawei and Leica representatives about their collaboration that resulted in the triple lens camera of the Huawei P20 Pro .
Watch the highlights of the visit in our video and read more details in our article – see below the main paragraphs:
- Leica History
- Huawei P20 Pro camera: why three lenses?
- Leica and Huawei cooperation for the P20 Pro camera
- Leica manufacturing process for high-end camera lenses
1/ Leica History
1849 -1911 – Ernst Leitz Optische Werke early years: microscopes and binoculars
The Leica history starts in 1849 when the young mechanic Carl Kellner founds the «Optisches Institute» (Optical Institute) in Wetzlar, Germany. In 1851, the company starts to produce its first microscopes that are noted for their quality and precision. In 1869, Ernst Leitz became managing director and added his name to the brand: The Ernst Leitz – Optische Werke – Wetzlar company is established.
By 1900, the Leitz factory counts 400 employees and produces 4000 microscopes a year and has expanded internationally with a branch in New York.
Just before the Leica adventure started in 1914, the company produces its first binoculars in 1907, reaches the 950 employees and the 9000 microscopes a year mark by 1910.
In 1911, Oskar Barnack was hired by Ernst Leitz, from the department of microscope where he was working at competitor Carl Zeiss in Yena. In 1912, mathematician Max Berek came onboard, and draw the first Leitz lens for cameras.
1913- 1925 The birth of the 35 mm Leica camera
The big breakthrough happened in 1913, when Oskar Barnack designed the “Liliputkamera” in his spare time, officially known as the Ur-Leica, the first prototype of a small format 35 mm camera. In 1914, he built a second prototype of the UR-Leica that Ernst Leitz II takes on a trip to New York.
The first prototype of the “Lilliput camera” from 1913, officially known as the UR-Leica camera, was originally built as a light meter to measure the exact exposure time for Barnack’s larger movie camera.
The goal was to test small batches of 35 mm movie film to avoid wasting the precious material. The 35 mm film, widely used since the end of the 19th century, became a standard for the movie industry in 1909.
When realizing that the “Lilliput camera” delivered high image quality, Oskar Barnack used it to shoot its first still photograph in 1913, at the Eisenmarkt (Iron Market) in Wetzlar, Germany (see photo below).
The second prototype of the Ur-Leica developed in 1914 is currently exhibited at Leica headquarters, (photo & in the video) and Ernst Leitz II, the second son of founder Ernst Leitz I, shot one of its first photos in the streets of New York (below).
At the time, professional photographers used large and heavy plates cameras that required prolonged exposure times (several minutes) and were inconvenient to move around.
The Ur-Leica solved those problems since it was light, small and able to shoot with faster shutter speed. The 1914 New York street photo is perfectly sharp and shows people walking, a result that large plate cameras could not deliver without blurring the moving subjects.
The Ur-Leica was not the first 35 mm camera, several prototypes were developed around the early years of the 20th century, even before the first Barnack’s Lilliput device, but none of them were either popular or widely available. With that design, the German engineer created several innovative features that marked photography history forever.
Oskar Barnack invented the standard for 35 mm still photography, with the 24×36 mm negative format (improved from the 18×24 motion picture size) in a 36 exposure roll film, today’s industry standard that was defined, that was defined by the length of his outstretched arms (according to Leica).
Unlike the movie camera, the film transport system was horizontally oriented. Other innovations included a focal plane shutter with speed of 1/40s and 1/20s and the coupling of film winding and shutter cocking. Additionally, he introduced the daylight reloadable film cassette.
More info on the Ur-Leica specs here.
In 1924, Ernst Leitz II took the risk to lead the company into mass production, to give birth to the Leica I in 1925. The product name is a combination of the words Leitz and camera. Introduced at the Leipzig Spring Fair, it featured a non-interchangeable Leitz Anastigmat 50 mm f/3.5 lens designed by Max Berek in a collapsible mount.
The Leica I became very popular, and its lens, later re-branded Elmax (Ernst Leitz, Max Berek), became world famous when Berek used a new type of glass for its successor, the Elmar 50 mm f/3.5. The viewfinder was mounted on top of the camera body, there was no rangefinder, and the shutter speed ranged from 1/25s to 1/500s.
1932 -1953 The legend is born
With the Leica II launched in 1932, Oskar Barnack introduced a rangefinder coupled with interchangeable screw-mounted lenses integrated into the camera body. The rangefinder is a very important part of the company history since Leica still manufactures rangefinder cameras today: the Leica M-series. The Leica II featured seven shutter speeds ranging from 1/20s to 1/500s, the rangefinder and the viewfinder were separated.
In 1954, the Ernst Leitz company launched its most iconic product, the Leica M3. The M3 was the first to combine the viewfinder and the rangefinder, that automatically displayed bright-line frames for the area covered by 50, 90 and 135 mm focal length.
It introduced the M-mount, a bayonet mount for interchangeable lenses that is still used today by some manufacturers. Film winding was made easier by the replacement of the knob with a rapid winding lever. In fact, Leica states that the M3, is still the reference to all the M-cameras built since then.
Since that date, Leica continued to develop many more models until today’s latest M-series, the Leica M10.
At the start of our visit our visit, we stopped in the lobby, in front of the 36 iconic photos, shot with Leica cameras since 1914, and I was amazed to recognize a few of them including the legendary portrait of Che Guevarra, by Alex Korda. You can check the collection on the Leica website here.
2/ Huawei P20 Pro camera: why three lenses?
To date, the P20 Pro features the most complex camera system available in a smartphone, and it is co-branded with Leica. In addition to the triple-lens rear shooter, the Huawei P20 Pro offers a 24-megapixel front camera.
What sets the Huawei P20 Pro apart from the competition is its complex three-lenses rear camera system combined with its NPU unit integrated to the Kirin 970 processor, which powers, among other things, the AI-driven camera software.
Camera 1: 40 MP RGB camera with a f/1.8 aperture
f/1.8 aperture in a high-end smartphone is not an extremely impressive number by itself as you can find better paper-specs out there: (f/1.5 (S9), f/1.6 (V30) or f/1.7 (S8). However, the aperture is not an absolute metric but relative to the sensor size. Huawei’s camera has a sensor with nearly twice the surface area of the Galaxy S9’s.
I shot impressive night photos in Milan before our visit of Huawei’s flagship Experience Store. In low-light conditions, The P20 Pro uses pixel-binning to increase the signal to noise ratio by reducing the final resolution from 40MP down to 10MP. LG successfully used a similar technique with its LG V30S update. Many sensors are capable of this, but unfortunately, only a handful of OEMs use the binning functionality because it lowers the resolution. For Huawei, going from 40 to 10 MP works. For others, going from 16 to 4MP is a much larger trade-off.
Low light performance and Ultra long exposure – multi-frame technique
When it comes to low-light performance, Huawei is also introducing an ultra-long exposure of 4 seconds for low-light photos. The principle is based on a variant of the multi-frame noise-reduction technique and HDR photography used by many top phones such as the Pixel 2 and S9: take a lot of photos with low ISO and fast shutter speed, and combine them into a bright, low-noise final image.
Camera 2: Light/Monochrome
The 20 Megapixel f/1.6 (monochrome, no RGB filter) camera is dedicated to capturing the brightness (light intensity) of the image. Removing the RGB layer from the sensor and thus making it monochrome enables more light to hit the sensing areas.
This camera module supplements the RGB camera, and its image will be combined with the RGB image to improve its brightness accuracy. That might be why Huawei decided that the main RGB lens does not need a larger aperture. The additional detail from this camera could also be (somewhat) integrated into the final photo.
Camera 3: 8 MP with 3X optical Zoom (5X Hybrid Zoom) with hardware OIS
As you know, Apple introduced a 2X optical zoom with the iPhone 7 Plus, followed by Samsung shortly after, in the Note 8. Huawei is outdoing both Samsung and Apple by integrating a 3X optical zoom in the P20 Pro and Mate RS. With this new lens, Huawei is able to create a 5X hybrid zoom (optical+digital) which beats everything the competition has to oppose."HUAWEI IS OUTDOING BOTH SAMSUNG AND APPLE BY INTEGRATING A 3X OPTICAL ZOOM"
When it comes to Zooming, especially in good lighting conditions, nothing beat the optics specifications. 3X optical zoom is simply sharper than 2X. It is really that simple. The third lens gets hardware Optical Image Stabilization because it is much needed when you zoom all the way.
The zoom provides amazing results: when I tried it in broad daylight in the huge courtyard of the Louvre museum I was able to capture details of the sculptures on the roof of the palace I could not imagine would be reproduced so sharply with a smartphone camera.
There are many other aspects of the new Huawei P20 Pro that we might go back to later, but things like Super Slow Motion at 960 FPS and Artificial Intelligence (AI) driven photo are on the menu.
The camera automatically recognizes 19 types of scenes by the camera such as blue sky, cat, food, greenery and more. You can set the AI on and off form the settings, and when the scene category name appears on the screen, you can dismiss the AI settings from there as well by clicking on the X in front of the name.
When I tried the AI, mostly for food shots and outdoors, it automatically detected “greenery,” “blue sky” “food,” and “night.”. I liked the results in AI mode, in comparison with similar shots in regular Auto mode. The ability to discard the AI settings right from the screen is great as it does not fit some people’s tastes. Sometimes the AI mode tends to saturate more some colors, which I like.
Huawei P20 Pro Camera and how it compares to the competition:
See our P20 Pro review – we plan on updating the review again in the next days.
3/ Leica and Huawei cooperation for the P20 Pro camera
Huawei and Leica started to collaborate in 2016 on the Huawei P9, and during our visit, both teams took the time to talk a little more about the partnership.
Left: Michael Röder, Senior Communication Manager, Leica
Middle: Florian Weiler, Project Manager Optical Design, Leica Camera AG
Right: Peter Gauden, Global Senior Product Marketing Manager, Huawei CBG
When it was asked who does the lens manufacturing of the Huawei P20 Pro, “Huawei or Leica?”, Florian Weiler, Project Manager Optical Design, Leica Camera AG said “Neither nor. We have suppliers, but Leica does not produce the lenses.” It was explained that the suppliers are selected both by Leica and Huawei, and most of them are in Asia.
Leica is world-famous for its high-quality and compact M lenses made of glass, so naturally, the conversation started on that topic.
When asked about designing the lens, the Leica representative replied that “it is a close cooperation between Huawei and Leica” that takes place during a “complex iteration process,” according to Florian Weiler, Project Manager Optical Design, Leica Camera AG. It sounded like both the Leica and Huawei teams frequently traveled between Germany and Asia during the design and manufacturing processes.
Leica confirmed that the lens in the Huawei P20 Pro does not feature any glass, and they are made of plastic instead, which is a very common practice for smartphones.
Leica is praised for its high-precision craftsmanship of expensive large glass lenses and optical systems, so it makes sense that the manufacturing of mass-produced small smartphones plastic lenses is done in Asia
Although we could not get any detailed information about “who does what” during our interview, it sounded like Leica played a key role in the design decisions for the P20 Pro’s optical system. Later, the German company confirmed that its involvement was mostly focused on the main rear camera system.
Then the Artificial Intelligence topic came on the table as it is a central feature of the P20 Pro shooter. Florian Weiler from Leica explained that when it comes to image quality, his company is certainly interested in artificial intelligence because the software can sometimes “have a better judgment” (his words).
He mentioned the example of white balance which can be complex to execute properly for a human photographer, so AI can be useful to make proper assessments.
Camera Software and image processing
When it comes to the image processing software, which is a key element of the P20 Pro camera efficiency, experts from Leica worked closely with the Huawei team to develop the fine-tuning of the image quality.
Peter Gauden, Global Senior Product Marketing Manager, Huawei CBG, said “it is not just the lenses [they collaborate on], both companies share the same philosophy” that the image quality demands “the combination of the entire camera ecosystem”.
He added that the P20 Pro’s image capturing system development was a “joint collaboration […] all the way from the sensor”. From the camera hardware to the lenses, including the parameters used by the Huawei chipset, and the “fine-tuning of the software on the back of it.”
We could not get a more precise description of each company’s contribution to the software, even when I asked how many engineers on both sides were dedicated to the task. It is highly probable that neither Huawei nor Leica want to disclose their “secret sauce” to the competition.
Leica and the future of mobile photography
We asked Leica about how it sees its future in the context of mobile photography and if they would consider collaboration with other mobile makers.
Leica made it clear that the exclusive cooperation with Huawei involved a lot of knowledge transfer between both sides and because the level of achievement with the P20 Pro is so high that the German manufacturer does not want to lose the benefits of the partnership.
On the manufacturing side, some high-end Leica lenses can take up to four hours to make, in that regard, the camera manufacturer does not have the mass-production capabilities required for smartphones. Only Huawei’s supply chain has the ability to produce the camera modules for the 6 million P20 and P20 Pro that were sold globally (as of June 2018).
4/ Leica manufacturing process for high-end camera lenses
Spherical lenses (the shape of the lens is part of a sphere) are easier and cheaper to manufacture than aspheric ones (the shape is not part of a sphere), but they produce spherical aberrations.
Aberrations cause light rays passing through the center of the lens and those passing through the edge of the lens to have different focal points, resulting in lower image quality and requiring correction systems.
Aspherical surfaces minimize or avoid aberrations and are also “the key to the compact size of M-Lenses” because they need far less correction, they reduce the number of elements required in the camera’s optical system.
Aspherical lenses are expensive because they require the use of high-precision grinding and polishing technology while spherical lenses can be easily molded and use less complex manufacturing processes.
Leica lens manufacturing is made of more than “30 production processes”, the lenses are “ finished by hand.” Finally, before the lens is released in the market, “60 quality controls check are performed” by experienced technicians.
Step 1: Grinding
A round-shaped piece of optical glass is grinded to be shaped to concave or convex form, and then the radius is measured with high-precision. The radius size is important to create the desired light path in the lens element. Then the radius is measured with a high-precision tool.
Step 2: Centration
The lens is centered so that the outer edge is cut to the right circumference, which defines the mechanical axis that must be aligned with the optical axis of the lens, defined by the curvatures of the optical surfaces. The amount of decentering in a lens is the physical displacement of the mechanical axis from the optical axis. Laser technology delivers precision measurement of centration.
Step 3: Polishing.
In the video, the high-precision stylus traces the profile of the physical aspherical lens element and measures the deviation from the perfect aspheric equation, the deviation tolerance at Leica is 0.1 micrometer.
Leica uses computer-controlled (CCP) and magneto-rheological (MRF) precision polishing to finalize the surface of its aspheric lenses. This process requires the use of a magnetic-sensitive fluid (MR fluid or MRF) whose viscosity changes in milliseconds when subjected to a magnetic field.
MRF delivers high-performance surface previously unattainable with standard polishing techniques and enables an optimized production of high precision optical aspheric elements.
The control panel displays in red the thicker surfaces and in blue the thinner ones, the thickness is shown in a gradient from red to blue.
Step 4: Coating
Anti-reflective coating reduces reflections and increases light transmittance. At Leica, the coating process enables the reduction of light reflection to 0.4% (from 4% reflection loss before coating). Other coating processes in lens manufacturing allow better color rendition as well.
Step 5: Manual cementing doublets
Leica uses cemented doublet lens elements to correct light diffraction while maintaining the final optical system’s size compact. The Leica’s cemented doublet lens is made by manually gluing two simple lenses together.
The hard part is to make sure that no bubbles form between the two elements, which would result in blurry images. The doublet is aligned during the glue solidification process powered by Ultra-violet light.
Step 6: Manual lacquering
the black lacquer is applied on the lens outer ring reduces the light reflection and increase the optical system efficiency. More information about the hand-crafted M lenses from a 2012 interview of Stefan Daniels, Leica.
Manufacturing process sources: Leica, Edmund Optics (link, pdf), QED technologies, Thorlabs, ESCO Optics, J.H. Burge and Katie Schwertz from College of Optical Sciences, University of Arizona, Panasonic (Know-Hows website), Wikipedia