The U.S. Mint continued to produce Proof Sets this year as it had stopped making them in 1942. The 1950 Proof Sets had the lowest mintage for Proof coins produced from 1950-1958. This year was the first year in which you begin to see a strong Cameo appearance on coins as the Mint is now improving the quality of the coins they produce.
In 1936 and 1942 the Mint also produced Brilliant cents but none had a strong Cameo appearance to warrant the Deep Cameo designation. For the 1950 Proof Lincoln cent however the Mint did produce coins with a Deep Cameo appearance as this is the first date in the series where PCGS has graded a Deep Cameo coin. Coins displaying Deep Cameo surfaces are very scarce and were probably some of the first coins struck or struck from freshly polished dies.