These are not off-the-shelf consumer CCDs. These are highly specialized CCDs designed expressly (at Brookhaven National Lab) for this camera - they're essential

These are not off-the-shelf consumer CCDs. These are highly specialized CCDs designed expressly (at Brookhaven National Lab) for this camera - they're essentially unique.[0] They have to meet very challenging specifications, such as high quantum efficiency (what percentage of photons get detected) across a broad spectral range, fast readout with low noise, and minimal persistence across exposures (meaning that if you image a bright star, you don't see a faint trace of it in the next exposure). As I understand it, there was no single company that could even manufacture the required number of CCDs on time, so two different manufacturers had to be chosen. 0. https://www.bnl.gov/lsst/ccd.php https://www.bnl.gov/lsst/ccd.php