I bought a used late 2015 Imac 27 inch from someone. Colours look fantastic but I'm not 100% satisfied with the contrast, especially the black level. For example: it looks like black letters (especially on the top area of the screen) aren't as deep solid black as I'd like them to be. The black level isn't bad, but when I compare them to an old 24" inch TN display I have next to it, it falls slightly short. And that's a very cheap LCD. I'm wondering if I just got unlucky with this unit. Up on searching I found this review, that explains what I notice: "The contrast ratio is okay at 740:1 (average for workstation notebooks, for example) and is definitely sufficient for nice pictures." https://www.notebookcheck.net/Apple...ch-M390-Late-2015-Retina-Review.155325.0.html However, most other reviews measure around 1100:1 which is really what it should be. Does anyone know what might be going on? I've played around with the calibration profiles but that didn't solve it.