How do I import DSLR Jpegs into Photo Library?

Richard, the current version of macOS 14 Sonoma offers to export as HEIC, finally. Have a look at the first item Kind" in the Export dialog. We are now having the options "JPEG, HEIC, TIFF, PNG".

The user guide does not yet mention the HEIC option.

I just pop my SD card into a USB card reader (because my Air doesn't have one built in) and drag the files to the Photos icon. If Photos is running when you connect the SD card, it may automatically offer to import all the pictures on the card. Since I don't delete pictures from my SD card before it gets full, I close Photos when I insert the card.

HEIC is sort of the preferred format for Apple-- it isn't higher quality than jpeg, but it's a more efficient compression. Oddly, Photos doesn't offer HEIC as an export format.

Photos don't change the format of an imported picture. It keeps the original picture unchanged, and it remembers the editing steps so it can recreate them for viewing, printing, and exporting. Except for thumbnails and previews, it may never need to create a jpeg or HEIC copy.

Currently my Photo Library is set to HEIC files. Is at simple as changing this to JPEG, losing a bit of the quality and storage in the process?

To clarify: your Photo Library is not set to anything. it accepts HEIC and Jpeg as well as tiff and many forms of raw file. There is nothing to change

Both formats, HEIC and JPEG are using a lossy compression. Converting HEIC to JPEG and vice versa will cause some loss in quality. I would avoid unnecessary conversions, unless you need a photo in a different format.

Oops-- I'm still on Ventura -- my Air is getting more and more angry about it.