The 35mm Apo-Summicron-SL f/2 Asph. & the Other Apo-Summicron-SL Lenses
The first prototype of the 75mm APO-Summicron-SL arrived in January 2017. I had several copies of that lens over the next year whilst Leica refined the autofocus. I have to say that the image quality never really needed much work.
The lens was finally announced in January 2018. I tried to be sensible and resist, but after a couple of months (and some anguish as to whether to buy the 75 or the 90mm), I cracked and at the end of March I bought my own copy of the 75mm.
Since then I’ve used it for weddings, events, food, nature, street, and especially for portrait work. It’s never failed me and the results have always been splendid.
In my opinion it was technically the best lens I had ever tested (perhaps now exceeded by this 35mm APO SL?). More than that, it still manages to have real character.
I haven’t written about the 75mm as it somehow never seemed to be the right moment. My job here is to write about the newly announced 35mm APO-Summicron-SL, but everything I say here is also relevant to the previous 75 and 90mm, and I’m sure will also be relevant to the upcoming 50mm, as well as the 21, 24 and 28mm wide angles.
Apochromatic Lenses An Apochromat, or apochromatic lens (APO) is a photographic or other lens that has better correction for chromatic and spherical aberration.
Leica has been making APO lenses for some time. As far as I can gather, the first of these were the apochromatic Elcan-R series designed by Walter Mandler in 1965 for the US Military. Only 25 of each focal length were produced. The first publicly available APO lens was the 180mm APO-Telyt-R f/3.4 from 1975, which was in production until 1998.
There were various telephoto lenses in the 70s and 80s, culminating in the 180mm APO-Summicron-R f/2 in 1994 (with which Peter Karbe was involved) and the 90mm APO- Summicron-M f/2 in 1998.
Peter Karbe wanted to apply the technology to normal focal length lenses, and the first two of these were the 50mm Summilux-M ASPH (which actually has APO characteristics) in 2004 and the 75MM APO-Summicron-M in 2005.
A 16-year project to make a perfect 50mm lens came to fruition in 2012 when the 50mm APO-Summicron-M was produced. This lens was a Summicron (f/2) rather than a Summilux (f/1.4) because it’s easier to make slower lenses to a higher quality – and of course a smaller size as well.
Large Fast Lenses Since the maturity of digital imaging, and especially with the very high resolution modern sensors, lens sizes seem to have increased exponentially (One only has to think of the Zeiss Otus and the Leica 75mm Noctilux-M).
If you then also need autofocus, the motors needed for auto- focus get bigger as the lens elements get bigger. The Leica 50mm Summilux-SL f/1.4 being a case in point.
So, the concept of a range of incredibly high quality Summicron f/2 lenses for the L-mount was born. The 75mm and the 90mm were released early in 2018.
APO Lenses, Contrast & Depth of Field The almost zero aberrations (especially chromatic aberrations) in the new Summicron-SL lenses means a big increase in contrast where the image is in focus. As you move away from the point of perfect focus the contrast drops sharply. This means that the transition between ‘sharp’ and ‘bokeh’ is defined more quickly and results in smoother out of focus areas than in conventional lenses.
I have a diagram drawn for me by Peter Karbe in my notebook, but below is the graph from the Leica website comparing the 75mm APO-Summicron-SL with the 75mm Summilux-M. The result of this is not just that the 75mm APO-Summicron-SL is sharper (it certainly is), but that it has apparently the same DOF as the 75mm Summilux-M.
So we have a series of modestly sized autofocus lenses for the L-mount which perform better than their aspherical competitors and without any depth of field disadvantage. Of course, they gather less light, but that isn’t often a problem with modern sensors.
Currently the 75 and 90mm APO-Summicron-SL lenses are available. The 35mm has already begun shipping and the 50mm will be shipping later in 2019. The wider angle lenses are promised for 2020.
SL, 1/60 sec at f/2.0, ISO 320
SL, 1/60 sec at f/2.8, ISO 320
SL, 1/60 sec at f/2.2, ISO 50
The 35mm APO-Summicron-SL f/2 ASPH This brings us to the new 35mm Summicron-SL. It has exactly the same form factor as the previous lenses (and the future ones as well). It has the same dual synchro-drive motor which delivers fast and silent autofocus. It focuses down to 0.3 meters giving a magnification ratio of 1:5, which is the same as the 75 and 90mm with their longer minimum focus distance.
Like all the other lenses it has an E67 filter thread and weighs a little over 700 grams – this means that it handles nicely on the Leica CL as well as on the SL. Build quality is exemplary (as it should be at this price). The lens is weather sealed to a high degree like all the other SL lenses.
I received my test copy towards the end of January this year, just before we headed off to China to celebrate the Chinese New Year with our son, his girlfriend and her parents (a tea farming family near Longjing). We stayed in a little hotel just on the edge of the West Lake in Hangzhou.
There were lots of long walks in the surrounding countryside and many celebration meals. Sadly the weather was less than photogenic; we only had one sunny afternoon, otherwise, it was 3°C (37°F) and either misty or raining.
A foodie pic to whet your appetite. Taken with the 75mm APO-Summicron-SL. SL, 1/160 sec at f/2.0, ISO 640
I used the 35mm extensively, both in China and in the UK before and after the trip. I’ve used it on both the SL and the CL (where it works nicely as a very high quality 50mm f/2).
The lens focuses quietly and quickly on both the SL and the CL, even in low light situations. As with the other SL lenses,you can manuallytweak the focusing after half pressing theshutter to achieve auto focus.
Manual focusing itself is ‘focus by wire’, but it’s very smooth and works well. For still photography I’m very fond of the ‘acceleration’ on the manual focus ring, although I hope that there will be a firmware option later on to allow you to make it linear, which is important for video shooters.
I’ve not seen any chromatic aberration on any images - and I’ve been shooting a lot into bright light. Some flare is occasionally evident when shooting straight into the sun, but it’s minimal and easy to handle.
CL, 1/1600 sec at f/3.5, ISO 100
SL, 1/1600 sec at f/2.0, ISO 50
CL, 1/200 sec at f/2.0, ISO 100
Image quality is exemplary. I did a series of tests at different apertures and distances and the lens seems to be perfectly sharp at all times, right to the corners. This is borne out by the amazing MTF charts for the lens. As Peter Karbe’s memorable T-Shirt has it: ‘Stop down for What?’.
Theoretically the quality falls off a tiny bit at 0.5 meters and closer, but I was unable to detect it. The bokeh is creamy and soft, and seemingly never ‘nervous’.
CL, 1/60 sec at f/2.0, ISO 3200
Price & Manufacturing This is an expensive lens, and I suppose there will be many who complain that it’s only an f/2, Having discussed this at length with Leica, I understand that to get this sort of quality both the materials (primarily the glass) and the precision of manufacture, together with re- ally stringent quality control, are absolutely paramount; these things do not come cheap.
Conclusion The 35mm APO-Summicron-SL is a wonder of a lens with many virtues, and, as far as I can see, no vices. Fantastic for almost all situations – especially street, event and landscape – it joins the other two Summicron-SL lenses as a tribute to Leica’s determination not to sacrifice anything for quality.
With the advent of the L-mount consortium, I’m certain that these lenses will be in demand for use on the Panasonic and Sigma cameras, as well as on the Leica CL and SL. I can envisage a real shortage of supply, so get your order in soon before the Panasonic S1R guys realize how good it is!
Acknowledgements: Many thanks to Peter Karbe for patiently explaining the wonders of the APO Lenses. Thank you also to Stefan Daniel and Stephan Schulz for checking my facts. Special thanks to my wonderful Emma for putting up with so much whilst I take the pictures and write these articles.