Chapter 3
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With these considerations it is possible to create and define the image effects that you want.
If the main subject is encircled by objects in the fore- and bak- kground, you can visually emphasize the relationship between the subjects and even make it appear as threatening, as is the case with cars that seem to collide. If the photographer needs the impression of masses, the selection of subject matter beco- mes important. Pictures at the beach show the piling up of beach guests and pictures in shopping centers show the mas- ses of
On the other hand, it is also possible to isolate the subject com- pletely from the surroundings. Wide open, the depth of field is quite shallow and by adding light and shapes to the composi- tion we can create very interesting images. The shallow depth of field is enhanced by the following phenomenon:
A 180 mm lens has a lateral magnification of 3.6x compared to a standard lens. The subject is enlarged 3.6 times in its height and width dimensions. But what happens to the third dimen- sion: depth? The optical laws tell us that the axial magnification (the depth) is the square of the lateral magnification. The depth magnification is now 12.96x. In photographic practice we see this as an abrupt change in the unsharpness gradient. The cir- cles of confusion are also enlarged! This effect is not related to the
An image point always has a certain extension or radius that looks like a small circle or disc of light. If the radius is small enough, the eye will interpret it as a point. The largest circle that is seen as a point is called the circle of confusion and its diameter is 0.03 mm on the negative.
The superb performance of the 180 mm f/2.8
these distances there is a reduction of 1.8x in the luminance of the negative. The automatic exposure programs of Leica R cameras compensate for this effect, but when you make a manual exposure, it is wise to take this into account. The occa- sionally expressed wish for a true macro lens with a focal length of 200 mm is practically fulfilled with this combination. A bit outmoded nowadays, but still useful is the Bellows Attach- ment
The focal length of the 180 mm f/2.8
With an
This lens has somewhat higher contrast in the center of the image, but it is not so good at the comers and in the outer zonal areas. The 280 mm lens however, is usable as a
LEICA | Picture: Erwin Puts |
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