Economies of scale: why a shared AF system for Nikon’s D5 and D500 is good and bad
By now, you’ve undoubtedly seen the news: Nikon announced two new, professional-level DSLRs at CES. The D5 continues the legacy of Nikon’s full-frame flagship line, which began with the D3. The D500 has similar roots: it is the direct descendent of the D300, the top-of-the-line DX-format camera that arrived alongside the D3 in 2007. The relationship between the D5 and D500 is analogous to that of the D3 and D300, but everything has been turned up. Where the D3 and D300 had 12 megapixels, the D5 and D500 have 20. The D3 and D300 shot continuous exposures at 9 and 6 FPS, respectively, while the D5 and D500 shoot at 12 and 10 FPS. But perhaps the most important feature introduced in the D3 and D300 was the shared, 51-point autofocus system, a version of which would live on in new Nikon cameras up until this moment, as they have officially been made obsolete thanks to the 153-point system just announced with the D5 and D500.
Of all the features these two cameras bring, like 4K video (in a Nikon!), the new AF system is perhaps the most important. Recent mirrorless cameras have made huge advancements in autofocus technology. Case in point: Sony’s A7R II and its 299-point system. In the meantime, DSLR autofocus has lagged behind in number of points, but still outperforms mirrorless cameras when it comes to shooting moving subjects. And that, of course, is where the new D5 and D500 aim to excel. Of the 153 AF points, 99 are cross-type, meaning they are sensitive to both vertical and horizontal lines which should mean faster performance. The higher number of points also means a denser overall array, which should aid the system in tracking moving subjects. On paper, this is a revolutionary jump in DLSR autofocus—but is it everything we want?
As a long-time Nikon shooter, it was never so much the number of AF points that disappointed me, but rather the overall area of coverage. When an AF system is developed to be shared across formats, then coverage area will always be limited on the larger of the formats. I owned a D300 and loved how I could set an active focus point almost to the edge of the frame. Once I moved to the D3, I was somewhat saddened to see I could no longer do that. With a larger frame, the AF area becomes relatively smaller; given that full-frame is about twice the surface area of APS-C, it’s a significant difference. The shared AF system of the D5 and D500 will result in the same issue.
However, there are benefits to a shared system that go beyond cost savings. To be clear, there is nothing unique or different about Nikon’s approach here compared to other manufacturers, but I felt it was worth talking about given the significance of this advancement over previous technologies. If Nikon had instead developed bespoke AF modules for each camera, chances are neither would be as good. Would we have 99 cross-type points? Probably not. Would we have a system that could function in -4 EV conditions? Doubtful. By combining resources to build and test a single system, the result should be a fast, accurate, reliable, and affordable solution. Still, it might be a bit of a let down for those of us hoping that 102 additional points would mean a significant increase in full-frame AF coverage. Oh well, focus and reframe, focus and reframe…