It is well know that the effect of the parallax is to increase in the apparent zenith distance of a celestial object. Unless we consider its effect into account, the predictions can go wrong considerably, particularly in the case of eclipses. Since the obscurer and the obscured at the same distance in the case of a lunar eclipse, the effect of parallax can be completely ignored. However, in the case of solar eclipse, parallax significantly influences the precision with which we can predict the instant of opposition, the duration of the eclipse, as well as its magnitude.

Clearly recognizing this fact, the astronomers of both Indian and Chinese tradition have paid enough attention to consider its effect into their computational scheme. In the Indian tradition, the astronomers have broadly divided the effect of parallax in two parts namely the parallax in longitude (called lambana) and the parallax in latitude (called nati). Whereas in the Chinese tradition, the effect of parallax seems to have been discussed in three parts: Qi difference, Ke difference and Time difference. The first two are also referred to as the north-south difference and the east-west difference respectively. During our presentation, we will try to compare and contract the approach taken by the two traditions in handling the effect of parallax in computing solar eclipses.