Introduction Erythrons are organized into erythroblastic islands. Tracing the course of cellular differentiation requires a reliable method for quantification of the morphological characteristics of these cells as they are prone to adopting highly changing phenotypes. Aim of the work The primary objective of this study was to show the applicability of Adobe Photoshop software in cytomorphometry, and the second objective was to summarize the ultrastructural characteristics of the cells forming the erythroblastic islands. Materials and methods Ultrathin sections of bone marrow were prepared from 10 albino rats and then the digitized electron microscopy images of erythrons were stored. Adobe Photoshop was used to measure the cytomorphometric parameters in the electron micrographs of these developing cells. The area occupied by any cellular component could be specified and compared directly from the histogram using the ‘Magnetic Lasso Tool’. The area pixel size and luminosity of all pixels within the selected area were recorded and the data were subjected to statistical analysis. Results The study reports a straightforward pixel-based cytomorphometric method that gives objective information about pixel values of area size and luminescence. The recorded analytical values of a nucleated erythron differed significantly from those of its preceding stage, and the average cytoplasmic luminosity of mature RBCs was 67.62% that of reticulocytes. In addition, the developmental features of erythrons were explored. Conclusion When the input material is standardized, Adobe Photoshop gives affordable and accurate measurement options that may be available for a diverse range of histomorphometric applications.