I'm getting back into photography after a long hiatus. The last time that I did any photography was with Snow Leopard.
I used a CF card reader to import photos from my camera's card and, without my asking, Photos opened. I looked through Photos preferences but could not find any way to prevent this. Likewise, Finder preferences drew a blank.
Is there any way to prevent Photos from automatically opening when I mount a card reader? To add to the annoyances, I had Photos import the RAW files that were on the CF card and it converted them to JPG, which is exactly what I don't want. Fortunately, those RAW files were still on the CF card and I was able to download them, unchanged, to a folder of my choice from the disk image of the card.
OS 10.15.3, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365