\lambda,$$ where $x$ is the surface brightness of 1 zodi of exozodiacal light in magnitudes per unit solid angle, and $n$ is the typical number of zodis assumed for all stars. Expanding all dependencies on $\lambda$ and $D$, we find $$\label{CRbexozodi_equation_expanded}
    {\rm CR_{b,exozodi}} = F_0\, n\, 10^{-0.4x}\, \frac{\pi^2 X^2}{4}\, \lambda_V^2\, T\, \Delta \lambda,$$ such that the exozodiacal light’s count rate is independent of telescope aperture.

Note that ${\rm CR_p}$ and ${\rm CR_{b,\star}}$ are proportional to $D^2$ while ${\rm CR_{b,zodi}}$ and ${\rm CR_{b,exozodi}}$ are independent of $D$. Thus, we may be tempted to think that exozodis will affect larger apertures less. However, for a given star ${\rm CR_p}$ and ${\rm CR_{b,\star}}$ are proportional to $d^{-2}$ while ${\rm CR_{b,zodi}}$ and ${\rm CR_{b,exozodi}}$ are independent of stellar distance, as expected for resolved sources. Because larger apertures have shorter exposure times, missions with larger apertures will eventually observe more distant targets, for which the exozodi problem becomes worse. Thus the dependence of the yield on parameters like exozodi level and contrast cannot be intuited from the count rate equations above, and will be controlled by the combination of these equations and the target list selected for observation.

[ccl]{} $D$ & $8$ m & Telescope 