Determination of Absorption By Q-Method for JHK Photometry

In this work, we consider the application of the Q-method to determine an absorption for the 2MASS photometric system. We determine the non-reddened sequence based on the Pleiades and Praesepe stars. We also propose a method for selecting the segment of the non-reddened sequence for stars belonging to a cluster. To test this method, we simulate the luminosity functions of clusters with non-uniform absorption distribution in the region.