Leica 11645 manual Effective Distortion Ymm

LEICA SUMMARIT-M 75 mm f/2.5 4

Distortion

	[%]		Relative Distortion					Effective Distortion
5
						Y'[mm]
4
3						12
2
1						9
0
-1						6
-2
-3						3
-4
-5						0
0		5	10	15	20	0	3	6	9	12	15	18
				Y' [mm] =	21.0000							X'[mm]

Vignetting
		Vignetting
100[%]
80				5.6
				4.0
				2.5
60
40
20
0
0	5	10	15	20

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 magnification. The image height of 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- tes the appearance of straight horizontal and verti- cal lines in the picture.

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 image height. 100% means no vignetting.