The Allure of the iMac
As the Apple iMac has evolved into a more attractive device, photographers and designers have been tempted by the increasingly alluring form factor, more powerful processors, and the larger, higher resolution screens. They have asked with each generation of new iMac if it was finally fit-to-purpose for serious image editing and graphics work. Until recently the answer was a resounding “No”. The iMac lacked sufficient backlight dimming to be used in low light level imaging environments, and the screen technology did not offer consistent color and density as the viewer moved side to side or up and down. The glossy screen looked great, but reflected too much light, making it difficult to view subtle images on it unless in a perfectly dark room, and even then, the user’s own reflection on the screen caused problems. So I was obliged to tell users that the only practical way to use an iMac as a quality imaging station was with a second, higher quality display connected to it; which was not the configuration most people had in mind.
The previous generation of iMacs finally included backlight controls that allowed the built-in display to be dimmed sufficiently to be used in low light editing environments. But the screen type still did not offer accurate viewing off-axis, the reflection issue was still present, and uniformity across the screen could still be an issue.
Apple is forever striving to improve their products, and the upcoming generation of iMacs will solve many of the limitations that kept iMacs from being acceptable imaging stations in the past.
The Promise of the Next Generation
The key change to the next generation of iMacs is that they will now include IPS (in-plane switching) screens, to offer excellent color consistency over a very wide viewing angle. The screens should also offer improved uniformity. How much of an improvement will have to wait for testing, but it should be sufficient to allow for imaging uses. And the new iMacs will be individually factory calibrated for precise gamma and white point. Gamma is the tone response curve from black to white, and is responsible for assuring that the screen shows smooth gradients, and accurate brightness for all colors. White point is a global color correction that adjusts all colors to an accurate balance.
These items are two of the three key components in accurate screen calibration. Recent Apple displays, including the iPad3, iPhone5, and 15″ Retina display MacBook Pro all have been designed to produce a very close approximation of the sRGB color gamut. It is a reasonable assumption that the new iMacs will continue this trend.
What This Means to the Graphics User
Having precisely calibrated gamma and white point and a close-to-sRGB gamut in a display means that, even without custom calibration or color managed applications, images in sRGB (the standard for the web, and the color space most consumer digital cameras and smartphones attempt to match) and video using the common Rec 709 video standard will all be displayed correctly. The iPad 3, iPhone 5, and 15″ Retina display MacBook Pro offered this color gamut, but did not have the precise gamma and white point correction the new iMacs will offer, so were reasonably accurate in displaying sRGB and Rec 709 files, but still required calibration to correct the gamma and white point for professional caliber color display. The new iMacs should be able to do this right out of the box.
Whether custom calibration will improve the iMac display’s initial state is yet to be seen. But the iMac displays will be factory calibrated with a spectro-radiometer, just as Datacolor Spyder display calibrators are, so recalibration over time using a hardware calibrator should be aligned nicely to bring the iMac color back to the same standard it was calibrated to at the factory.
The Potential Deal-Breaker
There is one factor that may interfere with the use of the upcoming iMacs as imaging workstations. If Apple is so proud of the in-factory calibration of the displays that they write this data permanently to the video card, and do not allow the user to flash updated data from display calibration tools to the video card, then the improved accuracy of the new iMacs will be relatively short lived, and offer no way to keep the device in calibration over time. There is no indication that Apple will break with current open standards for display profiles and calibration data, but it is worth looking into before purchasing a new iMac specifically for serious imaging work.
The sRGB Taboo
Marketing for wide gamut displays has convinced most serious image editors that sRGB is not a sufficiently large color space for their imaging work. The reality of the matter is that AdobeRGB shares the same Red and Blue primaries as sRGB. The only area where it displays increased color saturation is in saturated Greens. These fluorescent greens won’t be clipped from your files by using an sRGB display, they will simply not show their increased saturation on screen. It is not difficult to live with this display limitation in most types of image editing. Professional image editing is very effective on the Retina display MacBook Pro, with its IPS screen and sRGB gamut. Using the new iMac would offer a larger screen (though not as many pixels) at the same color gamut, and would offer consistency between desktop and laptop for Retina MBP owners.
Other Features Valuable for Imaging
Current imaging processes involve large, high bit files, and demand lots of disc space, lots of memory, fast data access, fast data transfer, powerful graphics processors, and powerful main processors. The new iMacs offer excellent specs in all these areas. Of particular interest is the option to use hybrid drives, where a spinning hard drive and a smaller amount of solid state memory are combined in one virtual disk. More frequently used apps and files will automatically be moved to the much faster solid state memory, speeding commonly used processes.
Video Editing Looks Promising Too
The features above are all valuable for video editing as well as still imaging. Thunderbolt file transfer speeds, SSD drive options, Core i7 processors, Turbo Boost processor speed tuning, and the advanced NVIDIA graphics cards are of particular value for video editing.
Other Possible Alternatives
The MacPro tower has not had a major overhaul in years. If an update is released, then the advantages of more drive space, flexibility in adding special cards and more memory, and other advantages will make this an excellent machine for demanding processes such as advanced video editing. But these special features will be far less necessary for still imaging.
In the other direction, the 15″ Retina display MacBook Pro is the first Apple laptop capable for serious image editing. It’s resolution of 2880 by 1800 actually exceed the resolution of the new iMacs; but on a much smaller screen. The MacBook offers even less flexibility for user-customization than an iMac, but it offers the advantage of portability. Even more portability is available with the 13″ Retina display MacBook Pro, further compromising screen real estate for device portability, but the 13″ model now being released should have all the accuracy and resolution advantages of the previously released 15″ Retina MBP, just with a smaller screen.
For those who prefer a standalone desktop monitor, for various reasons, including wider gamut, the Mac Mini offers a cost effective single-display solution, though external monitors can be used with the iMac and MacBook Pro models as well. Apple has made it progressively more difficult to calibrate an external wide gamut monitor with recent OS versions, but they have been made aware of this issue, and we expect that they will correct the situation in future OS updates.
Not Just a Prettier Face
No doubt the new iMacs will be the most attractive iMacs ever. And many serious imagers will be tempted to buy one as an imaging machine. Until it is possible to test the new iMacs it is impossible to be sure just how well they will function for such uses. But on first inspection, it appears that they may make a very good image editing system, at accessible price points. Once it is possible to test the new iMacs, a follow-up article will provide further information.