If the descriptions of ‘Leica M’ and ‘Leica SL’ camera ranges above have left you confused, here’s a quick guide: These cameras have two separate lens ranges.
Leica makes two series of full frame cameras the traditional Leica M rangefinders and the ultra-modern mirrorless Leica SL series (above). Summaron (f/5.6): The LEICA SUMMARON-M 28 mm f/5.6 is a one-off, a classic, super-compact (hence the small maximum aperture) Leica M lens re-engineered and re-issued for a modern audience.There are a couple of Elmar M series primes, including a macro lens, and the interesting 16-18-21mm Tri-Elmar-M, which is not so much a zoom lens as a lens with three focal length settings, all with an f/4 maximum aperture. Elmar (f/4): Elmar lenses have a maximum aperture of f/4.There is also a Super-Vario-Elmar 16-35mm lens in the Leica SL range, with a maximum aperture of f/3.5 at the widest zoom setting. Super-Elmar (f/3.4-3.8): The next aperture step is the Elmar lens, but in between there is a category of Super-Elmars (Elmar lenses but faster) in the f/3.4-3.8 range.(They are variable aperture lenses, but they are f/2.8 at the wide angle end of the zoom range.
There is only one Elmarit in the Leica M lens range, but there are two Elmarit zooms, or Vario-Elmarits, in the SL lens range. Elmarit (f/2.8): Elmarit lenses have a maximum aperture of f/2.8.In the Leica M range, these are smaller and lighter than Summilux lenses but still pretty fast. Summicron lenses have a maximum aperture of f/2. Summarit (f/2.4): This is an in-between f/2.4 lens that’s not quite a Summicron, but still faster than an Elmarit (the next category), and there are several in the Leica M range.Most of the Leica SL prime lenses are Summicrons. Summicron (f/2): Summicron lenses have a maximum aperture of f/2.Summilux lenses are somewhat larger than the next category… These are mostly for the Leica M mount system, though there is a Summilux 50mm f/1.4 for the Leica SL range.