In a complexometric titration of metal ion with ligand $M \left(\mathrm{M}\mathrm{e}\mathrm{t}\mathrm{a}\mathrm{l} \mathrm{i}\mathrm{o}\mathrm{n}\right)+L\left(\mathrm{L}\mathrm{i}\mathrm{g}\mathrm{a}\mathrm{n}\mathrm{d}\right)\to C \left(\mathrm{C}\mathrm{o}\mathrm{m}\mathrm{p}\mathrm{l}\mathrm{e}\mathrm{x}\right)$ end point is estimated spectrophotometrically (through light absorption). If 'M' and 'C' do not absorb light and only 'L' absorbs then the titration plot between absorbed light $\left(A\right)$ versus volume of ligand 'L' $\left(V\right)$ would look like: