Top left: the modeled foreground spiral galaxy, VV 191b, determined by effectively subtracting out the modeled background elliptical galaxy. One can see the subtle outline of the background elliptical in this image. A radius of ∼14 kpc is overlaid in dotted black to show the extent of the rms annular profile. Top right: the JWST F090W image of VV 191 with the sampled sky with low S/N used to calculate its rms outlined in red. Bottom left: the annular rms profile of VV 191. Each annulus has a bin width of 5 pixels. Bottom right: histogram of the sigma-clipped sky region whose sample is shown above in the F090W image. The units are in megajanskys per steradian.