The $\ensuremath{\gamma}$-ray yield functions for the $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$ reaction have been studied from ${E}_{\mathrm{c}.\mathrm{m}.}=15 \mathrm{to} 23.7$ MeV and the $^{16}\mathrm{O}$ + $^{28}\mathrm{Si}$ reaction from ${E}_{\mathrm{c}.\mathrm{m}.}=20 \mathrm{to} 34.9$ MeV. Structure in the form of a broad oscillation was observed for some channels of the $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$ reaction, but for the $^{16}\mathrm{O}$ + $^{28}\mathrm{Si}$ reaction no structure was detected. It was also noted that the fusion-evaporation processes to high spin states of the residual nuclei play a greater role in the $^{16}\mathrm{C}$ + $^{28}\mathrm{Si}$ reaction than for $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$. These observations are consistent with a greater surface transparency in the case of the $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$ system.NUCLEAR REACTIONS $^{12}\mathrm{C}$ + $^{24}\mathrm{Mg}$, ${E}_{^{24}\mathrm{Mg}}=45\ensuremath{-}71$ MeV; $^{16}\mathrm{O}$ + $^{28}\mathrm{Si}$, ${E}_{^{28}\mathrm{Si}}=55\ensuremath{-}96$ MeV. Natural carbon and oxygen targets. Measured ${I}_{\ensuremath{\gamma}}(E)$.