power 4dLive 4D Results for Magnum 4D, Sports ToTo, DaMaCai 1+3D, Sabah 4D, CashSweep 4D, Sandakan 4D & SingaporeTwo lenses have power of (i) + 2 d (ii) -4D. What is the nature and focal length of each lens? b. An object is kept at a distance of 100 cm from lens of power -4D. Calculate the image distance.