Leica SUMMICRON-T 23 mm f/2 ASPH. User manual

LEICA SUPER ELMAR-M 21mm f/3.4 ASPH.
More than 30 years after the launch of Summicron-M 1:2/50 mm, which is still available, the Leica APO Summicron-M
1:2/50 mm ASPH. represents a totally new development. With its compact body - only marginally longer and slightly heavier than
the Summicron-M 1:2/50 mm, and with an almost identical diameter, it provides visibly higher image quality. On the Leica APO
Summicron-M 1:2/50 mm ASPH. the exceptional correction enables all aberrations to be reduced to a minimum level that is negli-
gible in digital photography. Its key features include excellent contrast rendition, all the way to the corners of the image, even with
a fully open aperture. The use of a „oating element“ ensures that this is retained, even for close-up shots. Vignetting is limited to
a maximum - i.e. in the corners of the image - of just 2 stops at full aperture in 35 mm format, or around 1 on the Leica M8 mo-
dels. Stopping down to 2.8 visibly reduces this light deterioration towards the edge of the image, with practically only the natural
vignetting remaining. Distortion is very low at a maximum of just 0.4 % (pin cushoin), which is practically imperceptible. A total of
eight lens elements are used to achieve this exceptional performance. To realize the apochromatic correction (resulting in a com-
mon focusing plane for three light wavelengths), three are made of glass types with high anomalous partial color dispersion, while
two of the others have a high refractive index. The aspherical surface of the rst lens in the rear group helps to reduce spherical
aberration and atten the image eld. While the optical construction in front of the aperture is a Gaussian type, the arrangement
of the lens elements behind it is similar to that in the Summilux-M 1:1.4/35 mm ASPH. This group comprises a „oating element“,
which is moved independently of the rest of the construction during focusing.
Summary: The Leica APO Summicron-M 1:2/50 mm ASPH. delivers exceptional picture quality and sets new standards in 35 mm
digital photography.
Optical design
1
LEICA APO-SUMMICRON-M 50 mm f/2 ASPH.
Asphäre
FloatingElement
Aspherical surface
Floating Element

LEICA SUPER ELMAR-M 21mm f/3.4 ASPH.
Engineering drawing
2
Technical Data
Angle of view (diagonal, horizontal, vertical) 47° / 40° / 27° (With Leica M8 models: 36° / 30° / 20°)
Optical design Number of lenses/groups: 8 / 5
Position of entrance pupil
(from bayonet ange): 24.4 mm
Focus range: 0.7 m to ∞
Distance setting Scales: Combined meter / graduation
  Smallestobjecteld:
approx. 271 mm x 407 mm (With Leica M8 models: 203 mm x 305 mm)
Largest reproduction ratio:
approx. 1:11.3
Aperture Setting / Function:
prex with click-stops, half steps
Lowest value:
16
Bayonet
Leica M quick-change bayonet
Lens hood Built-in, extendable by rotating
Dimensions and weight Length:
approx. 47 mm
Largest diameter:
approx. 53 mm
Weight:
approx. 300 g
Filter mount Female thread for screw-on E39 lters, non-rotating
LEICA APO-SUMMICRON-M 50 mm f/2 ASPH.

LEICA SUPER ELMAR-M 21mm f/3.4 ASPH.
MTF-graphs
The MTF is indicated at full aperture, at f/2,8 and f/5,6
at long taking distances (innity). Shown is the contrast
in percentage for 5, 10, 20 and 40 lp/mm accross the
height of the 35 mm lm format, for tangential (dotted
line) and sagittal (solid line) structures, in white light.
The 5 and 10 lp/mm will give an indication regarding
the contrast ratio for large object structures. The 20
and 40 lp/mm records the resolution of ner and nest
object structures.
tangential structures
sagittal structures
3
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,0
Apo-Summicron-M1:2,0/50mmASPH.Brennweite50mm
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,8
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100
Blende5,6
[%]
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Vignettierung
2,0
2,8
5,6
0 3 6 9 12 15 18 21
Y'[mm]
-5
-4
-3
-2
-1
0
1
2
3
4
5[%] RelativeVerzeichnung
0 3 6 9 12 15 18
X'[mm]
0
3
6
9
12
Y'[mm]
EffektiveVerzeichnung
f/2.0
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,0
Apo-Summicron-M1:2,0/50mmASPH.Brennweite50mm
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,8
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100
Blende5,6
[%]
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Vignettierung
2,0
2,8
5,6
0 3 6 9 12 15 18 21
Y'[mm]
-5
-4
-3
-2
-1
0
1
2
3
4
5[%] RelativeVerzeichnung
0 3 6 9 12 15 18
X'[mm]
0
3
6
9
12
Y'[mm]
EffektiveVerzeichnung
Aperture Stop 5.6
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,0
Apo-Summicron-M1:2,0/50mmASPH.Brennweite50mm
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,8
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100
Blende5,6
[%]
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Vignettierung
2,0
2,8
5,6
0 3 6 9 12 15 18 21
Y'[mm]
-5
-4
-3
-2
-1
0
1
2
3
4
5[%] RelativeVerzeichnung
0 3 6 9 12 15 18
X'[mm]
0
3
6
9
12
Y'[mm]
EffektiveVerzeichnung
LEICA APO-SUMMICRON-M 50 mm f/2 ASPH.
f/5.6
f/2.8

LEICA SUPER ELMAR-M 21mm f/3.4 ASPH.
Distortion
Distortion is the deviation of the real image height (in
the picture) from the ideal image height. The relative
distortion is the percentage deviation. The ideal image
height results from the object height and the magnica-
tion. The image height of 21.6 mm is the radial distance
between the edge and the middle of the image eld for
the 24 mm x 36 mm format. The graph of the eective
distortion illustrates the appearance of straight horizon-
tal and vertical lines in the picture.
Vignetting is a continous decrease of the illumination to-
wards the edges of the image eld. The graph shows the
percentage lost of illumination over the image height.
100% means no vignetting.
Vignetting
4
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,0
Apo-Summicron-M1:2,0/50mmASPH.Brennweite50mm
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,8
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100
Blende5,6
[%]
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Vignettierung
2,0
2,8
5,6
0 3 6 9 12 15 18 21
Y'[mm]
-5
-4
-3
-2
-1
0
1
2
3
4
5[%] RelativeVerzeichnung
0 3 6 9 12 15 18
X'[mm]
0
3
6
9
12
Y'[mm]
EffektiveVerzeichnung
Relative Distortion
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,0
Apo-Summicron-M1:2,0/50mmASPH.Brennweite50mm
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,8
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100
Blende5,6
[%]
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Vignettierung
2,0
2,8
5,6
0 3 6 9 12 15 18 21
Y'[mm]
-5
-4
-3
-2
-1
0
1
2
3
4
5[%] RelativeVerzeichnung
0 3 6 9 12 15 18
X'[mm]
0
3
6
9
12
Y'[mm]
EffektiveVerzeichnung
Eective Distortion
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,0
Apo-Summicron-M1:2,0/50mmASPH.Brennweite50mm
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Blende2,8
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100
Blende5,6
[%]
0 3 6 9 12 15 18 21
Y'[mm]
0
20
40
60
80
100[%] Vignettierung
2,0
2,8
5,6
0 3 6 9 12 15 18 21
Y'[mm]
-5
-4
-3
-2
-1
0
1
2
3
4
5[%] RelativeVerzeichnung
0 3 6 9 12 15 18
X'[mm]
0
3
6
9
12
Y'[mm]
EffektiveVerzeichnung
LEICA APO-SUMMICRON-M 50 mm f/2 ASPH.
f/5.6
f/2.8
f/2.0

LEICA SUPER ELMAR-M 21mm f/3.4 ASPH.
Depthofeldtable
5
Vergrößerung
0,7 0,690 - 0,710 0,686 - 0,714 0,681 - 0,721 0,673 - 0,729 0,662 - 0,743 0,649 - 0,760 0,629 - 0,792 1/11,3
0,8 0,787 - 0,814 0,782 - 0,819 0,774 - 0,828 0,764 - 0,840 0,750 - 0,858 0,733 - 0,882 0,706 - 0,926 1/13,2
1 0,979 - 1,023 0,971 - 1,032 0,958 - 1,046 0,943 - 1,065 0,920 - 1,096 0,894 - 1,137 0,853 - 1,214 1/17,1
1,2 1,169 - 1,233 1,157 - 1,247 1,139 - 1,268 1,117 - 1,297 1,085 - 1,345 1,047 - 1,409 0,991 - 1,531 1/21
1,5 1,450 - 1,554 1,432 - 1,575 1,404 - 1,610 1,370 - 1,659 1,321 - 1,739 1,264 - 1,850 1,181 - 2,071 1/26,8
2 1,910 - 2,099 1,878 - 2,139 1,830 - 2,205 1,771 - 2,300 1,688 - 2,459 1,595 - 2,693 1,462 - 3,203 1/36,5
3 2,799 - 3,233 2,729 - 3,332 2,627 - 3,499 2,503 - 3,749 2,338 - 4,201 2,161 - 4,950 1,919 - 7,055 1/55,8
5 4,458 - 5,694 4,280 - 6,016 4,032 - 6,591 3,743 - 7,556 3,381 - 9,690 3,017 - 15,01 2,560 - 185,1 1/94,5
∞ 40,20 - ∞ 29,05 - ∞ 20,36 - ∞ 14,55 - ∞ 10,20 - ∞ 7,435 - ∞ 5,128 - ∞ 1/∞
16,0
Blende
4,0
Eingestellte Entfernung [m]
5,6 8,0 11,02,0 2,8
Blende 2,0
0123456
0.7
0.8
1
1.2
1.5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Blende 2,8
0123456
0.7
0.8
1
1.2
1.5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Aperture Stop Magnication
Distance Setting [m]
LEICA APO-SUMMICRON-M 50 mm f/2 ASPH.
Vergrößerung
0,7 0,690 - 0,710 0,686 - 0,714 0,681 - 0,721 0,673 - 0,729 0,662 - 0,743 0,649 - 0,760 0,629 - 0,792 1/11,3
0,8 0,787 - 0,814 0,782 - 0,819 0,774 - 0,828 0,764 - 0,840 0,750 - 0,858 0,733 - 0,882 0,706 - 0,926 1/13,2
1 0,979 - 1,023 0,971 - 1,032 0,958 - 1,046 0,943 - 1,065 0,920 - 1,096 0,894 - 1,137 0,853 - 1,214 1/17,1
1,2 1,169 - 1,233 1,157 - 1,247 1,139 - 1,268 1,117 - 1,297 1,085 - 1,345 1,047 - 1,409 0,991 - 1,531 1/21
1,5 1,450 - 1,554 1,432 - 1,575 1,404 - 1,610 1,370 - 1,659 1,321 - 1,739 1,264 - 1,850 1,181 - 2,071 1/26,8
2 1,910 - 2,099 1,878 - 2,139 1,830 - 2,205 1,771 - 2,300 1,688 - 2,459 1,595 - 2,693 1,462 - 3,203 1/36,5
3 2,799 - 3,233 2,729 - 3,332 2,627 - 3,499 2,503 - 3,749 2,338 - 4,201 2,161 - 4,950 1,919 - 7,055 1/55,8
5 4,458 - 5,694 4,280 - 6,016 4,032 - 6,591 3,743 - 7,556 3,381 - 9,690 3,017 - 15,01 2,560 - 185,1 1/94,5
∞ 40,20 - ∞ 29,05 - ∞ 20,36 - ∞ 14,55 - ∞ 10,20 - ∞ 7,435 - ∞ 5,128 - ∞ 1/∞
16,0
Blende
4,0
Eingestellte Entfernung [m]
5,6 8,0 11,02,0 2,8
Blende 2,0
0123456
0.7
0.8
1
1.2
1.5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Blende 2,8
0123456
0.7
0.8
1
1.2
1.5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Aperture Stop 2,0
Distance Setting [m]
Depth of Field [m]
Vergrößerung
0,7 0,690 - 0,710 0,686 - 0,714 0,681 - 0,721 0,673 - 0,729 0,662 - 0,743 0,649 - 0,760 0,629 - 0,792 1/11,3
0,8 0,787 - 0,814 0,782 - 0,819 0,774 - 0,828 0,764 - 0,840 0,750 - 0,858 0,733 - 0,882 0,706 - 0,926 1/13,2
1 0,979 - 1,023 0,971 - 1,032 0,958 - 1,046 0,943 - 1,065 0,920 - 1,096 0,894 - 1,137 0,853 - 1,214 1/17,1
1,2 1,169 - 1,233 1,157 - 1,247 1,139 - 1,268 1,117 - 1,297 1,085 - 1,345 1,047 - 1,409 0,991 - 1,531 1/21
1,5 1,450 - 1,554 1,432 - 1,575 1,404 - 1,610 1,370 - 1,659 1,321 - 1,739 1,264 - 1,850 1,181 - 2,071 1/26,8
2 1,910 - 2,099 1,878 - 2,139 1,830 - 2,205 1,771 - 2,300 1,688 - 2,459 1,595 - 2,693 1,462 - 3,203 1/36,5
3 2,799 - 3,233 2,729 - 3,332 2,627 - 3,499 2,503 - 3,749 2,338 - 4,201 2,161 - 4,950 1,919 - 7,055 1/55,8
5 4,458 - 5,694 4,280 - 6,016 4,032 - 6,591 3,743 - 7,556 3,381 - 9,690 3,017 - 15,01 2,560 - 185,1 1/94,5
∞ 40,20 - ∞ 29,05 - ∞ 20,36 - ∞ 14,55 - ∞ 10,20 - ∞ 7,435 - ∞ 5,128 - ∞ 1/∞
16,0
Blende
4,0
Eingestellte Entfernung [m]
5,6 8,0 11,02,0 2,8
Blende 2,0
0123456
0.7
0.8
1
1.2
1.5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Blende 2,8
0123456
0.7
0.8
1
1.2
1.5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Aperture Stop 2.8
Distance Setting [m]
Depth of Field [m]
Aperture Stop 2,8

LEICA SUPER ELMAR-M 21mm f/3.4 ASPH.
Blende 4,0
01234567
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Blende 5,6
012345678
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Blende 4,0
01234567
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Blende 5,6
012345678
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Aperture Stop 4,0
Distance Setting [m]
Depth of Field [m]
Aperture Stop 5,6
Distance Setting [m]
Depth of Field [m]
6
LEICA APO-SUMMICRON-M 50 mm f/2 ASPH.

LEICA SUPER ELMAR-M 21mm f/3.4 ASPH.
Blende 8,0
0 1 2 3 4 5 6 7 8 9 10
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Blende 11,0
0 1 2 3 4 5 6 7 8 9 10
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Aperture Stop 8,0
Depth of Field [m]
Distance Setting [m]
Blende 8,0
0 1 2 3 4 5 6 7 8 9 10
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Blende 11,0
0 1 2 3 4 5 6 7 8 9 10
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Aperture Stop 11,0
Depth of Field [m]
Distance Setting [m]
7
LEICA APO-SUMMICRON-M 50 mm f/2 ASPH.

LEICA SUPER ELMAR-M 21mm f/3.4 ASPH.
Leica Camera AG / Oskar-Barnack-Straße 11 / D-35606 Solms / Telefon [phone] / Telefax [phone]
www.leica-camera.com / inf[email protected]
Blende 16,0
0 1 2 3 4 5 6 7 8 9 10
0,7
0,8
1
1,2
1,5
2
3
5
∞
Eingestellte Entfernung [m]
Schärfentiefe [m]
Aperture Stop 16,0
Depth of Field [m]
Distance Setting [m]
8
LEICA APO-SUMMICRON-M 50 mm f/2 ASPH.