2 Questions about DCAM and CAMS: When do the CAMS start becoming common, is it different from each denomination??? When do the DCAMS start becoming common, is it different from each denomination???
From 1972 and on every proof coin is basically a CAM or DCAM. It's pretty easy to find 1971 CAM's but some denominations are very tough in DCAM.
DCAMs became the rule rather than the exception pretty much from 1976 on. The BIG difference (imo) happened in 2006 when the Mint began using a laser process to product the frosted cameo effect instead of the much more labor intensive process (and pleasing appearance) of sandblasting. I LOVE the silver proof sets issued between 1992-1998. Those sets represent old-school proof coin production at its very best. DCAM proofs from 1936-1964 are truly special!
1973 was the year the mint changed their policy. Prior to that the mint didn't care if Proofs had the cameo effect or not. After that they insisted that they all had it. Prior to '73, finding CAM or DCAM Proofs was difficult. From '73 and later, it became difficult to find Proofs that were not CAM or DCAM.