RGB simulations of the System 3 at z = 3.98 in Abell 2744. Top left: a high-resolution RGB simulation (2.5 mas/pix), where the red, green, and blue channels correspond to wavelengths of λ_e = 5, 3, and 2 μm, respectively; top right: the same high-resolution image, but monocromathic, constructed using the magnitudes of the host and the clumps in the JWST/F115W filter and convolved with the JWST/F115W PSF to illustrate the effect of instrumental resolution; middle left: an RGB image created by combining three HST ACS bands (red F814W, green F606W, and blue F435W), including realistic noise and sky background; middle right: an RGB image created by combining three HST WFC3/IR bands (red F160W, green F125W, and blue F105W), including realistic noise and sky background; bottom left: an RGB image created by combining three JWST NIRCam/SW channels (red F200W, green F150W, and blue F115W), including realistic noise and sky background; bottom right: an RGB image created by combining three JWST NIRCam/LW channels (red F444W, green F356W, and blue F277W), including realistic noise and sky background. The background level and effective exposure time are based on the data of Abell 2744 from real HST and JWST observations and are listed in Table 3. The red circle in each image highlights an example of a clump, illustrating how the instrument’s resolution is a limiting factor: while clumps appear as distinct structures in the HR image (see the zoom-in region shown at the bottom right of the figure), they become blended together in the JWST and HST observations. For each image, the origin of the coordinate system coincides with the center of the cluster, located at (RA: 3.586257 deg, Dec: −30.400172 deg).