The goal — see how well the new Apple iMac with Retina 5k Display conforms to system standards. Apple has always had quality displays, but is it good enough for VFX artists, Photographers, and Editors to do their color critical work? The quick and dirty — the display comes adjusted to an arbitrary target somewhere between the HDTV Standard of Rec.709 and the Computer Standard of sRGB. Technically, a computer display should be optimized for sRGB, which is very similar to our HDTV Standard of Rec.709 with the differences being:
– Computers use full range video, in 8-Bit Space: 0-255
– HD Standards use Legal Range Video, in 8-Bit Space: 16-235
– The Gamma response curves, or how fast it goes from black to white, is an approximately 2.2 in sRGB and 2.4 in Rec.709.
The Apple iMac with Retina 5K Display is shipped very close to the sRGB/709 Color Space, but the gamma was closer to a Power Function of 2.3 instead of the sRGB 2.2 or the Rec.709 2.4. This will result in computer content looking more contrasty and saturated than it should; however, as I state in the video review, the initial appearance of the display is extremely attractive.
To calibrate, we tried several different programs to create a custom ICC/Display Profile for the iMac. There were a number of bugs in getting the display to dial in at the bottom end of the gamma curve, but it did come within the tolerance of the specification, just not as perfect as we’re accustomed to. We’re working with various software vendors to attain a fix in a future update.
We also attempted to measure the full color capability, comparing it to the Adobe RGB standard, but the display is not capable of hitting that target; in fact, it didn’t even come close!
Most users will want to target sRGB, which the monitor will hit with proper calibration and we expect it to only get better as the various calibration tools improve to accommodate the latest OS X Yosemite updates and graphics cards utilized in the system