LensTip.com

The word 'Summicron' was created by joining two words, both taken from Latin. Summus means 'the highest', cron is taken from the name of the Greek god of time, Chronos, but also there is a type of glass called kron, that is characterized by a high amount of potassium oxide, a low refraction index, and also low dispersion. In the 50's of 20th century this type of glass became commonly available and the Leitz company decided to use it in its new optical constructions of lenses.

The first Summicron, a successor of the foldable Summitar with lanthanum glass, was launched in 1953, a tad before the launch of the Leica M camera that took place in 1954. It was a collapsible lens consisting of 7 elements positioned in 6 groups, offered with an M39 threaded mount. Not long afterwards, in 1956, that line was supplemented by the Summicron 2/50, also with 7 elements positioned in 6 groups, but already in a classic barrel and the Leica M mount.

Summicron-M's 2/50 lens desing from 1994.

The next generation of this model was shown in 1969 and, what's interesting, it came with a simpler optical construction of double gauss, consisting of 6 elements positioned in 4 groups. The fourth generation was launched in 1979 with the M letter in its name, in order to make the lens distinguishable from the instruments produced alongside with the Leica R mount. The fifth generation was introduced in 1994 and in 2013 we were shown the APO-Summicron M 50 mm f/2, a more complex construction with 8 elements positioned in 5 groups and one aspherical element inside.

Please Support Us If you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

During that time Leica has been producing Summicrons of different mount variants and different focal lengths. The most classic models came with 2/28, 2/35, 2/50, and 2/90 parameters. In the line-up you can also find instruments with less common mounts like the Leica Q (APO-Summicron 43 mm f/2 ASPH) or the Leica S (Summicron-S 100 mm f/2 ASPH).

Leica APO-Summicron-M 75 mm f/2 ASPH.

When it comes to the 75 mm focal length its history is rather short. Leica started to produce lenses with such untypical parameters only in 2005 (most likely starting the production in 2004) and immediately they launched one APO model so the APO-Summicron-M 75 mm f/2 APSPH, a construction consisting of 7 elements in 5 groups. In this lens they used special types of glass, among them fluorite (element 2) and anomalous partial dispersion glass with a high refractive index (element 4 that also features an aspherical surface).

Leica APO-Summicron-SL 35 mm f/2, Voigtlander Apo-Lanthar 50 mm f/2, Voigtlander Apo-Lanthar 65 mm f/2 Macro and Leica APO-Summicron-SL 75 mm f/2.

Also the newest Leica SL system had to feature some Summicrons but in this case the producer decided to launch immediately optically complex APO models – so far they have shown six such models and the following chart presents they all.

As you can notice, classic 2/28, 2/35, 2/50, 2/75 and 2/90 parameters were complemented by the ultra wide angle Super-APO-Summicron-SL 21 mm f/2 ASPH. What's more, in the timeline of Leica SL future launches we've seen also the APO-Summicron-SL 24mm f/2 ASPH but officially it has't been launched yet.

Our loyal Readers already know that in July 2025 we started the L-mount/SL-mount system optics tests. As first we handled the big and heavy Panasonic Lumix S Pro 50 mm f/1.4. In order to determine the maximum performance possible of the new system it was a big pleasure to add the tests of the Leica lenses as well. The first model we are going to take a closer look at is the APO-Summicron-SL 75 mm f/2 ASPH exactly.

We would like to thank the Leica Store in Warsaw for lending us one specimen for testing purposes.

You are also invited to get acquainted with our test procedure, described in the article "How do we test lenses?" If you feel it’s still not enough, please go to our FAQ section where you can find some further explanation.