The name Summilux is used by Leica and Panasonic Lumix to designate camera lenses that have a maximum aperture brighter than f/2, typically at f/1.4, but dimmer than f/1.25. The lens has been in production since 1959 and carries on to the present day.

The name Summilux is a combination of Summum, which is the Latin word for highest, while Lux is for light.^[1] The first Summilux was the 50 mm of 1959, followed by a new 50 mm Summilux design in 1961, whose optics remained unchanged until replaced by the 50 mm Summilux-M ASPH of 2004.^[2]

The Summilux lenses have a maximum f-number of f/1.4, f/1.5 or occasionally f/1.7. This means they are 1 to 1.5 f-stops slower than Leica's Noctilux lenses, but the Summilux lenses are smaller as a result.^[1] Summilux lenses are designed for low-light photography.

The Summilux lenses are less expensive than the Noctilux lenses, which has a smaller f-number.^[1] However they are bigger, heavier and more expensive than the Summicron.

For the Leica Q system (Leica Q, Leica Q2, Leica Q3)

• Summilux-M 28 mm f/1.7 ASPH.^[3][4][5]

For the Leica M mount

• Summilux-M 21 mm f/1.4 ASPH.^[6]
• Summilux-M 24 mm f/1.4 ASPH.^[7]
• Summilux-M 28 mm f/1.4 ASPH.^[8]
• Summilux 35 mm f/1.4^[9]
• Summilux-M 35 mm f/1.4 ASPH. FLE Version V^[10]
• Summilux-M 35 mm f/1.4 ASPH. FLE "Short Focus" Version VI^[11]
• Summilux 50 mm f/1.4^[12]
• Summilux-M 50 mm f/1.4 ASPH.^[13]
• Summilux-M 75 mm f/1.4^[14]
• Summilux-M 90 mm f/1.5 ASPH.^[15]

For the Leica R mount

• Summilux-R 35 mm f/1.4^[16]
• Summilux-R 50 mm f/1.4 1st version^[16]
• Summilux-R 50 mm f/1.4 2nd version^[16]
• Summilux-R 50 mm f/1.4 3rd version – 1997 (ROM contacts)^[16]
• Summilux-R 80mm f/1.4^[16]

For the Leica L Mount

• Summilux-TL 35 mm f/1.4 ASPH.^[17]
• Summilux-SL 50 mm f/1.4 ASPH.^[18]

For the Four Thirds mount^{[a 1]}

For the Micro Four Thirds mount^{[a 1]}

• Panasonic Leica DG Vario-Summilux 10–25 mm f/1.7 ASPH.^[19]
• Panasonic Leica DG Summilux 12 mm f/1.4 ASPH.^[20]
• Panasonic Leica DG Summilux 15 mm f/1.7 ASPH.^[21]
• Panasonic Leica DG Summilux 25 mm f/1.4^[22]
• Panasonic Leica DG Summilux 25 mm f/1.4 II ASPH.^[23]

• Summilux.net lens review site www.summilux.net
• Overgaard Leica 35mm Summilux article www.overgaard.dk/leica-35mm-Summilux-M-ASPH-f-14.html/
• Overgaard Leica lens compendium of all Summilux lenses www.overgaard.dk/leica_lens_compendium.html/