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1.The Lamegon 5.6/55
The lens has a focal length of 56 mmand is designed for taking survey
photographs80 mm•~80 mm in size. Its relative aperture is f:5.6.
1.1 Geometric Properties
Focal length and size of pictureprovidea 79 g angle of view, horizontallyand vertically.
The diagonal angle of view is100 g. This wide angle has beenchosen
deliberately. When photogrammetry isem-ployed for special jobs, the problemoften
requires the photographing of aslarge anarea as possible with a relativelyshort
distance between camera and object.Theshort distances between camera andobject
are governed by the prevailingconditionsfor photography. The necessity ofcovering
as large an object space as possibleislargely dictated by economicconsiderations.
As few stereo models as possibleshould berequired to cover an object, so asto render
ubsequent plotting economical. Ontheother hand, the requirement that thein-
formation obtained be gatheredsimultaneouslyoften means that the whole object
has to be photographed in a singlemodel.The same arguments apply to thesurveying
of events, which likewise have to becoveredby a single pair of stereophotographs when
only one camera is employed.
The wide angle of view involvescorres-pondingly severe demands on theplanarity
of the photographic emulsionemployed, ofcourse, if the full size of thepicture is to
be utilized.
The lens has very low distortion. Whenfocused for very long distance thedistortion
is no more than •}3 microns.
Free international Shipping
The items are shipped from Moldova (Eastern Europe) and normal delivery time is:
- to Europe - about 10-20 days ,- to USA about 10-25 days ,- rest of the world - 10-30 days
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