The Leica 35mm f2

APO Summicron M Asph

Jonathan Slack March 4th 2021



Biker Boy

Leica M10-R  ISO 100 1/1000th f2.4  Apo-Summicron-M 1:2/35 ASPH


About 10 or 11 years ago I went to Solms for a visit, I was a little early, and when I arrived the receptionist told me that Jesko was in a meeting and would be a bit late, and would I like to fill up the time playing with this lens. Of course.


The lens was a 50 Summicron, and there had been rumours of a replacement, so I took it at face value. I wandered around outside taking a few shots, and then sat down and put them on my computer. I'm not sure that my jaw actually dropped, but I was certainly gobsmacked, the images had a real clarity with wonderful bokeh, they just pinged out at me.


Fen Morning

Leica M10-R  ISO 100 1/350th f6.8  Apo-Summicron-M 1:2/35 ASPH

Of course, this was my first sight of the 50 APO Summicron M, and to give myself credit, I immediately realised how special it was, even when expecting something 'standard'.


Before that my only experience of APO lenses was the 75 APO Summicron M, which was already a firm favourite of mine. That lens also combines creamy bokeh with real precise sharpness. Every time I see someone use the word 'sterile' in conjunction with this lovely lens it hurts afresh!


Since that day we have seen a whole range of APO Summicrons for the L mount, and these also have been characterised by this combination of wonderful bokeh and stunning sharpness. Absolutely the opposite of 'sterile' these lenses produce a consistent and lovely look, not harsh at all, just right.


Shingle Street Lagoon

Leica M10-R  ISO 100 1/750th f6.8  Apo-Summicron-M 1:2/35 ASPH

Now we have the fourth Apochromatic M lens (after the 90, 75 and 50 Summicron lenses). The Apo-Summicron-M 1:2/35 Asph. I had the lens for a month from September last year.


Although looking at the first shots wasn't quite such an epiphany as the 50 APO (I was expecting to be blown away) it was still a revelatory experience!


Reading Peacefully

Leica M10-R  ISO 100 1/250th f4.8  Apo-Summicron-M 1:2/35 ASPH

Apochromatic correction

This is the term used to describe the reduction of colour aberrations in lenses, it requires special glass and is necessary if you want to produce the very best MTF figures.


For many years Leitz had their own glass production facility, and it was here that early glass materials to minimise colour aberrations were developed. Walter Mandler used these in the development of the early APO lenses.


Estuary of the River Ore

Leica M10-R  ISO 100 1/1000th f5.6  Apo-Summicron-M 1:2/35 ASPH

The 180mm APO-Summicron was the first APO lens developed for the consumer market and was introduced in 1994. The intention was to get the best possible performance wide open, implementing APO technology to achieve this. This lens has become a legend, and now changes hands for £7,000 to £8,000 in good condition.


During the 90s Leica made a number of other APO R lenses including the 180 f2.8 Elmarit-R, the f4 280mm APO-Telyt-R, and the 400mm and 560mm APO-Telyt-R modules.


These APO glass elements are not easy to handle during production and during this period Leica became experienced in implementing the technology,



Leica M10-R  ISO 160 1/60th f4  Apo-Summicron-M 1:2/35 ASPH

The first APO lens for the M system was the 90mm APO-Summicron-M Asph, released in 1998. Here they combined Apochromatic correction in combination with newly developed aspherical surface polishing processes.


The 135mm APO-Telyt was also released in 1998.


The 75 mm APO-Summicron-M Asph was released in 2005, and in addition to APO and Aspherical technologies, it included a floating element, just like it's brother lens the 50 summilux Asph.


The fourth APO M lens was the 50 mm APO-Summicron-M, and this is the lens I referred to in my introduction, Thorsten Overgaard in his lens compendium refers to it as 'The World's best 50mm'. I think that was almost certainly true on it's release in 2012,


Since then Leica have mostly been concentrating on the APO-Summicron range for the L Mount, at the time of writing 5 lenses are available: 90, 75, 50, 35 and 28mm the 24 and 21mm lenses are scheduled to appear during the next year or so.


Middle Fen Sunrise

Leica M10-R  ISO 100 1/350th f4.8  Apo-Summicron-M 1:2/35 ASPH

Apo-Summicron-M 1:2/35 Asph

Leica have pulled out all the stops with this lens.

There are 10 elements consisting

3 Aspherical lens elements (with 4 aspherical surfaces)

6 elements using Apochromatic glass

3 elements made of glass with a high refractive index.


In addition they have developed a new focusing mount capable of focusing down to 0.3m. From 0.7m to infinity is rangefinder coupled with a similar throw as other classical 35mm M lenses. From 0.7 to 0.3 metres you will need to use Live view or the EVF for focusing (or an SL camera).



Leica M10-R  ISO 100 1/125th f2.4  Apo-Summicron-M 1:2/35 ASPH

Remarkably the MTF figures for this lens are almost as good as those for the much larger SL 35mm APO, which, Peter Karbe feels, is the best 35mm lens available on the market today.


The lens diameter at 53mm is the same as the 50 APO.  Without the screw in lens hood the length is 40.9mm as opposed to the 50 at 47mm, with the lens hood attached it's 49mm. It weighs 305gm as opposed to the 300gm of the APO 50, so, to all intents and purposes it's the same size as 50mm.


MTF Curve Comparison between 35 APO-M and 35 APO-SL

F2 (top row) and f5.6 (bottom row)

Construction Comparison between 35 APO-M and 35 APO-SL

It was This Big

Leica M10-R  ISO 100 1/350th f2  Apo-Summicron-M 1:2/35 ASPH


Like it's sibling, the 35 is just a perfect match for an M camera, it's small and relatively light and beautifully made and finished. It has a thumb tab, but unlike the 50 it has a screw in lens hood, which is shorter than the one on the 35 summicron Asph, more like the lens hoods on the late lamented summarit lenses, or indeed the Leica Q.


The close focus is really useful, and if you don't have an EVF with you it's easy enough to focus using the LCD. On an L mount camera it's even simpler. I think perhaps I would have liked to have a slightly more positive step when focusing closer than the coupled rangefinder, but this is really nitpicking (and it might have changed on the production lens).


Is that the new Leica lens?

Leica M10-R  ISO 100 1/350th f4  Apo-Summicron-M 1:2/35 ASPH


Image Quality

Image quality is nothing short of magical; from f2 and also stopped down, it's consistent and without obvious flaws beyond a little vignetting. It's sharp right to the corners, with hardly any fall off, even at f2.


As is the case with other recent APO lenses the transition between the ultra high definition in focus to creamy bokeh out of focus area is gentle and swift.


Most of my test shots were with the M10-R (and all the ones in the gallery), there is no question that the 35 APO resolves well enough for the 40mp sensor (and the 48mp of the SL2).  I would imagine it is future proofed against higher resolution sensors in M and L mount cameras to come.


The Mouth of the River Ore

Leica M10-R  ISO 100 1/750th f8  Apo-Summicron-M 1:2/35 ASPH



Just like the APO-Summicron 50mm the 35mm is an expensive lens, this is because the glass is expensive and hard to make, the production is problematic and the tolerances are very tight. Making such a small lens of such good quality is not simple. Hence the cost. On the other hand, it is a lovely object, like a beautifully made wrist watch, perfect in form and function.


I've been lucky enough to have had several discussions and some email correspondence with Peter Karbe about both the M and SL APO Summicrons. I think that giving up the bragging rights of wide apertures in order to make the very best quality lenses is admirable. It has the added advantage of keeping the size down.


Shingle Street

Leica M10-R  ISO 100 1/750th f5.6  Apo-Summicron-M 1:2/35 ASPH


Leica has applied this philosophy over 15 years to produce 5 SL and 4 M APO Summicrons; lenses which are consistent in performance and 'look', a real asset for the serious photographer.


There is a feeling amongst many photographers that modern lenses don't have a 'soul' like vintage glass; that they all look the same.  I would really dispute that, and I think that these in particular have a lovely look and feel about them, quite unlike any other lenses I have used.


Dead Swan Lake

Leica M10-R  ISO 100 1/180th f5.6  Apo-Summicron-M 1:2/35 ASPH


Developing and manufacturing this 35mm lens also shows Leica's serious intentions for the M system going forwards. Perhaps this isn't a surprise, but it's nice to have it confirmed.


This is a significant lens announcement for Leica, but more than that it's a lovely lens of peerless quality. Something to be used as a standard lens by the discerning photographer for years to come.


Hear Ye

Leica M10-R  ISO 100 1/350th f5.6  Apo-Summicron-M 1:2/35 ASPH

Acknowledgement and Links


First of all to Emma, who continues to cook delicious meals and humour me whilst I'm hunched over my computer at the other end of the kitchen (or left behind on dog walks crouched over a bent stick!).


Special thanks to Peter Karbe who has been incredibly kind with his time and technical input with respect to Apochromatic technology and its history with Leica.

Thank you to Stefan Janssen who has been really helpful, responsive and forthcoming with information (and lenses!). Good Luck with Tiny.

Thanks also to Stefan Daniel and Jesko von Oeynhausen at Leica, always helpful and fun to deal with.

Thank you to Evris at Rock & Roll Straps for supplying the lovely Riviera strap in the image below (and so many more!).


My partner in crime Sean Reid has just published a long and detailed article based on long term field testing and comparison studio tests of the M APO 35/2.0 ASPH. Using an M10-R and M10 Monochrom, he compares the new lens side by side with the current M 35/2.0 ASPH and current M 35/1.4 ASPH. He also tested the resolution of the APO 35 on the Leica SL2. , Sean's reviews are always worth the price of entry, find them at



More Images Here

North Norfolk Coast

Leica M10-R  ISO 100 1/3000th f4.8  Apo-Summicron-M 1:2/35 ASPH


Leica M10-R  ISO 100 1/250th f4  Apo-Summicron-M 1:2/35 ASPH


Leica M10-R  ISO 100 1/320th f4.8  Apo-Summicron-M 1:2/35 ASPH

Orford Scallops

Leica M10-R  ISO 100 1/60th f4  Apo-Summicron-M 1:2/35 ASPH


Leica M10-R  ISO 200 1/60th f2  Apo-Summicron-M 1:2/35 ASPH

Jonathan Slack