Charged-only isolation ($p_{T}^{iso}$) in a cone of R=0.4 as a function of long shower shape axis  ($\sigma^{2}_{long}$) in p-Pb collisions at $\sqrt{s_{NN}}=8.16$ TeV. The isolation is obtained using ITS-TPC tracks. Electromagnetic showers are measured in the EMCal and DCal detector. Dashed lines indicate different regions used in the ABCD method to calculate the isolated prompt photon purity.