LEICA -M 21 mm f/1.4 ASPH. 1

The LEICA SUMMILUX-M 21mm f/1.4 ASPH extends Leica's series of high speed M lenses into the wide-angle range. It offers excellent performance over the entire image field even at full stop and in the close-up range thanks to a "floating ele- ment". Stopping down to 2.8 leads to an absolutely outstanding image quality, in fact, in comparison to the lens of the same focal length, its rendition is slightly more uniform across the image field. The vignetting typical of every optical system is naturally more apparent with a super wide angle lens, particularly a high speed one like this, than on standard lenses or those with a long focal length. At full stop with the 35mm format, its maximum - i.e. in the corners of the image - is around 3.2 aperture stops or, with the models and their slightly smaller format, around 1.9 aperture stops. Stopping down to 2.8 visibly reduces this light fall-off towards the image edges to 1.7 or 0.8 aperture stops. Stopping down further does not bring any noticea- ble additional reduction, as all that remains is essentially the natural vignetting. The maximum distortion of the lens is 2.3%, which in practical terms is negligible for the majority of photographic applications. A total of ten lens elements are used to achie- ve this exceptional performance. To correct color aberrations, five of these are made of glass types with anomalous color disper- sion (partial dispersion), while a further two have aspherical surfaces. To maintain performance in the close-up range, one group towards the rear of the optical system is a "floating element" that moves independently of the rest of the mechanism.

Summary: The LEICA SUMMILUX-M 21mm f/1.4 ASPH offers maximum image performance with a focal length / speed combina- tion previously unavailable in the M system. This extends the composition options of M photography, particularly for available light shots, but also thanks to a previously unattainable reduction in the depth of field in combination with large angles of view.

Lens shape

ASPH. Floating element LEICA SUMMILUX-M 21 mm f/1.4 ASPH. 2

Engineering drawing

Technical Data Angle of view (diagonal, horizontal, vertical) 92° / 81° / 59° Optical design Number of lenses/groups: 10 / 8 Focal length: 21.6 mm Position of entrance pupil: 24.4 mm (related to the first lens surface in light direction) Focusing range: 0.7 m to infinity Distance setting Scales: Combined meter/feet graduation Smallest object field: 685 x 1027 mm Largest reproduction ratio: 1:29 Aperture Setting/Function: With click-stops, half values available, manual diaphragm Lowest value: 16 Bayonet quick-change bayonet with 6 bit lens identification bar code for digital M models Filter mount Series filter VIII in lens hood Lens hood Seperate, screw-on type Dimension and weight Length: 66 / 77 mm (without / with lens hood) Largest diamater: approx. 69.5 mm Weight: approx. 580 g 100 100

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100 5 4 80 3 LEICA SUMMILUX-M 21 mm f/1.4 ASPH. 2 3 60 1 0 40 -1 -2 20 -3 -4 0 -5 MTF graphs 05101520 05101520

Aperture Stop 1.4 Aperture Stop 5.6 [%] [%] 100 100 100

80 80 80 12 60 60 60 100 100 9

40 40 40 80 80 6

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0 0 0 0 40 0 5 10 15 20 40 051015200 5 10 15 20 0369121518 Y' [mm] = 21.0 Y' [mm] = 21.0 20 20

1000 05 051015204 05101520 80 3 2 Aperture Stop 2.8 60[%] 1 100 5 0 The MTF is indicated both at full aperture and at 4 f/5.6 at long taking distances (infinity). Shown 40 -1 80 3 is the contrast in percentage for 5, 10, 20 and -2 40 lp/mm accross the height of the 35 mm film 2 20 -3 format, for tangential (dotted line) and sagittal 60 1 (solid line) structures, in white light. The 5 and -4 10 lp/mm will give an indication regarding the 0 0 -5 contrast ratio for large object structures.The 40 05101520-1 0510152020 and 40 lp/mm records the resolution of finer -2 and finest object structures. 20 -3 -4 sagittal structures ______tangential structures 1000 -5 0 5 10 15 20 05101520 80 Y' [mm] = 21.0 12 60 100 9

40 80 6 12 20 3 60 9 0 0 40 051015206 0369121518

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0 0 05101520 0369121518 100 100

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100 100 100 5 4 80 80 80 3 LEICA SUMMILUX-M 21 mm f/1.4 ASPH.2 4 60 60 60 1 0 40 40 40 -1 -2 20 20 20 -3 -4 0 Distortion0 0 -5 05101520 0510152005101520 05101520

Relative Distortion Effective Distortion [%] 100 5 100 4 Y'[mm] 80 3 80 2 12 60 1 60 9 0 40 40 -1 6 -2 20 -3 20 3 -4 0 -5 0 0 05101520 0 5 0510152010 15 20 0 3 6 9 12 15 18 Y' [mm] = 21.0 X'[mm]

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80 12 Vignetting 60 9

40 Vignetting 6[%] 100 100 Distortion is the deviation of the real image height 20 (in the picture) from the ideal image height. The 3 relative distortion is the percentage deviation. 80 80 5.6 2.8 The ideal image height results from the object 0 0 1.4 height and the magnification. The image height of 60 0510152060 0369121518 21.6mm is the radial distance between the edge and the middle of the image field for the format 24mm x 36mm. The graph of the effective distortion illustra- 40 40 tes the appearance of straight horizontal and verti- cal lines in the picture.

20 20 Vignetting is a continous decrease of the illumina- tion to the edges of the image field. The graph shows the percentage loss of illumination over the 0 0 image height. 100% means no vignetting. 05101520 0 5 10 15 20 Y' [mm] = 21.0

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0 0 05101520 0369121518 LEICA SUMMILUX-M 21 mm f/1.4 ASPH. 5

Depth of field table

Aperture Stop Magnification 1,4 2 2,8 4 5,6 8 11 16 0,7 0,661 - 0,744 0,648 - 0,762 0,630 - 0,790 0,605 - 0,837 0,574 - 0,910 0,534 - 1,050 0,493 - 1,308 0,438 - 2,275 1/28,7 0,8 0,749 - 0,860 0,731 - 0,884 0,708 - 0,924 0,675 - 0,991 0,636 - 1,098 0,586 - 1,316 0,535 - 1,765 0,469 - 4,314 1/33,3 1 0,918 - 1,099 0,892 - 1,142 0,855 - 1,211 0,806 - 1,333 0,749 - 1,545 0,679 - 2,039 0,609 - 3,457 0,523 - ∞ 1/42,6 1,2 1,081 - 1,350 1,044 - 1,416 0,993 - 1,527 0,926 - 1,734 0,850 - 2,120 0,759 - 3,219 0,671 - 9,613 0,565 - ∞ 1/51,9 1,5 1,315 - 1,749 1,259 - 1,864 1,184 - 2,068 1,087 - 2,477 0,982 - 3,381 0,859 - 7,657 0,746 - ∞ 0,615 - ∞ 1/65,8 2 1,678 - 2,483 1,585 - 2,729 1,465 - 3,201 1,317 - 4,339 1,162 - 8,347 0,991 - ∞ 0,840 - ∞ 0,675 - ∞ 1/88,9 3 2,318 - 4,277 2,139 - 5,088 1,922 - 7,085 1,670 - 17,48 1,424 - ∞ 1,170 - ∞ 0,961 - ∞ 0,747 - ∞ Distance SettingDistance [m] 1/135 5 3,334 - 10,14 2,970 - 16,51 2,560 - 243,7 2,125 - ∞ 1,736 - ∞ 1,368 - ∞ 1,087 - ∞ 0,817 - ∞ 1/228 ∞ 9,734 - ∞ 7,113 - ∞ 5,102 - ∞ 3,593 - ∞ 2,587 - ∞ 1,832 - ∞ 1,351 - ∞ 0,951 - ∞ 1/∞

Aperture Stop 1,4

0,7 0,8 1 1,2 1,5 2 3

Distance[m]Setting 5 ∞

0 1 2 3 4 5 6 7 8 9 10 Depth of Field [m]

Aperture Stop 2

0,7 0,8 1 1,2 1,5 2 3

DistanceSetting[m] 5 ∞

0 1 2 3 4 5 6 7 8 9 10 Depth of Field [m] LEICA SUMMILUX-M 21 mm f/1.4 ASPH. 6

Aperture Stop 2,8

0,7 0,8 1 1,2 1,5 2 3

Distance[m]Setting 5 ∞

0 1 2 3 4 5 6 7 8 9 10 Depth of Field [m]

Aperture Stop 4

0,7 0,8 1 1,2 1,5 2 3

Distance[m]Setting 5 ∞

0 1 2 3 4 5 6 7 8 9 10 Depth of Field [m]

Aperture Stop 5,6

0,7 0,8 1 1,2 1,5 2 3

DistanceSetting[m] 5 ∞

0 1 2 3 4 5 6 7 8 9 10 Depth of Field [m] LEICA SUMMILUX-M 21 mm f/1.4 ASPH. 7

Aperture Stop 8

0,7 0,8 1 1,2 1,5 2 3

Distance[m]Setting 5 ∞

0 1 2 3 4 5 6 7 8 9 10 Depth of Field [m]

Aperture Stop 11

0,7 0,8 1 1,2 1,5 2 3

Distance[m]Setting 5 ∞

0 1 2 3 4 5 6 7 8 9 10 Depth of Field [m]

Aperture Stop 16

0,7 0,8 1 1,2 1,5 2 3

DistanceSetting[m] 5 ∞

0 1 2 3 4 5 6 7 8 9 10 Depth of Field [m]

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