Leitz Camera invented the M bayonet which kept almost the same over the last 50 years.
Naming convention of Leica M lenses - the lens names are describing the maximum lens aperture
| Name | Maximum aperture |
| Noctilux | f/0.95 to f/1.2 |
| Summilux | f/1.4 |
| Summicron | f/2 |
| Summarit | f/2.5 |
| Elmarit | f/2.8 |
| Elmar | f/3.5 |
| Super-Elmar | f/3.8 |
| Elmar | f/4 |
| Hektor | f/4.5 |
Current Leica M lenses: http://en.leica-camera.com/photography/m_system/lenses/
Current line of Leica M lenses (Q1/2010)
| Name | Focal length / hor. angle | Aperture | Weight | Dimensions (L x D) |
| Wide-Angle Lenses | ||||
| TRI-ELMAR-M 16-18-21mm f/4 ASPH. | 16-18-21mm | f/4 to 22 | 335g | 62mm x 54mm |
| SUPER-ELMAR-M 18mm f/3.8 ASPH. | 18mm / 90° | f/3.8 to 16 | 310g | 58mm x 61mm |
| SUMMILUX-M 21mm f/1.4 ASPH. | 21mm / 81° | f/1.4 to 16 | 580g | 66mm x 69.5mm |
| ELMARIT-M 21mm f/2.8 ASPH. | 21mm / 81° | f/2.8 to 16 | 300g | 46mm x 58mm |
| SUMMILUX-M 24mm f/1.4 ASPH | 24mm / 74° | f/1.4 to 16 | 500g | 58.5mm x 61mm |
| ELMARIT-M 24mm f/2.8 ASPH. | 24mm / 74° | f/2.8 to 16 | 290g | 45mm x 58mm |
| ELMAR-M 24mm f/3.8 ASPH. | 24mm / 74° | f/3.8 to 16 | 260g | 40.6mm x 53mm |
| SUMMICRON-M 28mm f/2 ASPH | 28mm / 65° | f/2 to 16 | 270g | 40.8mm x 53mm |
| ELMARIT-M 28mm f/2.8 ASPH. | 28mm / 65° | f/2.8 to 22 | 180g | 30mm x 52mm |
| SUMMILUX-M 35mm f/1.4 ASPH. | 35mm / 54° | f/1.4 to 16 | 320g | 46.2mm x 53mm |
| SUMMICRON-M 35mm f/2 ASPH. | 35mm / 54° | f/2 to 16 | 255g | 34.5mm x 53mm |
| SUMMARIT-M 35mm f/2.5 | 35mm / 54° | f/2.5 to 16 | 220g | 33.9mm x 51.4mm |
| ---- | ||||
| Standard Lenses | ||||
| NOCTILUX-M 50mm f/0.95 ASPH. | 50mm / 40° | f/0.95 to 16 | 700g | 75.1mm x 73mm |
| SUMMILUX-M 50mm f/1.4 ASPH. | 50mm / 40° | f/1.4 to 16 | 335g | 52.5mm x 53.5mm |
| SUMMICRON-M 50mm f/2 ASPH. | 50mm / 40° | f/2 to 16 | 240g | 43.5mm x 53mm |
| SUMMARIT-M 50mm f/2.5 | 50mm / 40° | f/2.5 to 16 | 230g | 33mm x 51.5mm |
| ---- | ||||
| Telephoto Lenses | ||||
| APO-SUMMICRON-M 75mm f/2 ASPH. | 75mm / 27° | f/2 to 16 | 430g | 66.8mm x 58mm |
| SUMMARIT-M 75mm f/2.5 | 75mm / 27° | f/2.5 to 16 | 345g | 60.5mm x 55mm |
| APO-SUMMICRON-M 90mm f/2 ASPH. | 90mm / 23° | f/2 to 16 | 500g | 78mm x 64mm |
| SUMMARIT-M 90mm f/2.5 | 90mm / 23° | f/2.5 to 16 | 360g | 66.5mm x 55mm |
| APO-TELYT-M 135mm f/3.4 ASPH. | 135mm / 15° | f/3.4 to 22 | 450g | 104.7mm x 58.5mm |
| ---- | ||||
| Macro Lenses | ||||
| MACRO-ELMAR-M 90mm f/4 | 90mm / 27° | f/4 to 22 | 240g | 59mm x 52mm |
| Very fast lenses |
| Lightweight lenses |
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