I don't know what I was thinking at the time, but the camera I'm using is a Canon S100, not S20. I have no idea what I was thinking! I guess I wasn't.
Being retired and not using Lightroom (LR) on a regular basis, I have had no need to upgrade to Lightroom CC and currently still using LR v3.6. I recently upgraded the iMac OS to El Capitan and ever since doing so, I cannot import images from my camera (Canon S20) as in the past, connecting it directly with a USB cord. LR cannot see the camera when connected at all. What does automatically happen is that Apple's Photo software now automatically opens.
Since I prefer LR's raw features, I would like to continue with that, but I have not found any way to stop Photos from opening or LR to connect to my camera. Any suggestions? Or, is it time to scrap LR and resign myself to using Photos? Paying for Lightroom CC for the little I use it is not an option.
My camera also does not appear on the desktop as it had in the past.