Chyba vyplývajúca zo skutočnosti, že os laserového lúča nie je identická so základňou laserového diaľkomeru. Táto vzdialenosť je u rôznych diaľkomeroch rôzna, ale vždy je to niekoľko centimetrov. Keby sme ju zanedbali, tak by sme pri zámerách dlhých jednotky metrov urobili pomerne veľkú chybu pri určení sklonu. Viac napr.: Wikipedia - paralaxa

Comment of Mark Passerby:

There is no need for a cusom made offset target i.e. the Leica Disto A3 has a line that is cast along it. This line can be easily lined up with the point of Station A at the back of the Disto. This eliminates the need for a special made target because the laser line is in the direct path of Station A & B.

If you choose not to use a custom made offsetting target with any of these devices the important thing to remember is that the laser path has to be directly in the path of the two station points in order to get an accurate digital level/clino read.