24" Apple Cinema Display with 2019 iMac
I have an older 24" Cinema Display that I was using with my soon-to-be retired MacPro & I would like to use it with my new 21.5" iMac. I have a StarTech USB-C to Mini-Displayport adapter. I do get an image but it is extremely dark. Everything else seems to work OK through System Prefs.
It is unusable as dark as it is.
What can I do to adjust the brightness (& possibly other variables)?
Thanks!
Frank
iMac 21.5", macOS 10.14