On December 13, 2020 at 14:49, highfigh said...
The Spears & Munsell disc is a good place to start. Is it available at higher resolution?
Yes, they have a 4K HDR disc available. I have it.
There are also a couple more 4K HDR discs available.
I also have the Diversified Video Solutions (DVS) test suite. I paid over $100 for that, included downloads and discs for all the test patterns and material.
The Spears & Munsil disc came out right after I purchased that. The DVS suite is extremely comprehensive, but the S&M disc has everything anyone would need at a fraction of the cost ($39.99).