09-16-2020, 07:49 AM
You don’t really want a super high image quality setting because it makes files much larger for diminishing returns, your thumbs could wind up larger than the original images.
Assuming full screen the maximum thumbnail image size for a 5120x2880 screen would be ~671px with a 6/2 thumbnail layout (less for more thumbs shown). Your iMac Pro runs in hidpi mode but that makes it logically appear to be 2560x1440 with the end result of using the extra pixels to improve fidelity rather than display more data. Images are an exception so you still need thumbs at the same ~671px for the image to be sharp. As a comparison the 6k Pro Display XDR needs about 800px at 6/2, my MBP needs ~400px. The problem with big images (and why we don’t just use the original cover art scaled down) is that it uses a lot of memory and your browser needs to load them so it’s slower. Your ideal thumb size is the same size as the maximum image size at an iq value high enough to produce good results but low enough to produce small files. Another point of comparison - Photoshop’s “high” jpeg image quality default is 60. It might be helpful to re-size a few images yourself with Preview and tweak the quality slider to see how it affects the results so you can see at what point there’s a trade off between size and quality you’d be willing to make.
Assuming full screen the maximum thumbnail image size for a 5120x2880 screen would be ~671px with a 6/2 thumbnail layout (less for more thumbs shown). Your iMac Pro runs in hidpi mode but that makes it logically appear to be 2560x1440 with the end result of using the extra pixels to improve fidelity rather than display more data. Images are an exception so you still need thumbs at the same ~671px for the image to be sharp. As a comparison the 6k Pro Display XDR needs about 800px at 6/2, my MBP needs ~400px. The problem with big images (and why we don’t just use the original cover art scaled down) is that it uses a lot of memory and your browser needs to load them so it’s slower. Your ideal thumb size is the same size as the maximum image size at an iq value high enough to produce good results but low enough to produce small files. Another point of comparison - Photoshop’s “high” jpeg image quality default is 60. It might be helpful to re-size a few images yourself with Preview and tweak the quality slider to see how it affects the results so you can see at what point there’s a trade off between size and quality you’d be willing to make.
