It's always easy to fall into the trap of thinking, 'how could this get any better?' But it's not obvious what Nikon could do (or how much it'd cost) to make a DSLR significantly better than the D850. And, quite understandably, its focus is likely to be elsewhere.

The Nikkei, Japan's most prestigious financial newspaper, has reported that Nikon is exiting the DSLR market and is no longer developing new models. Nikon itself put out a statement saying it hadn't announced such a move and would still make and distribute DSLRs, but didn't deny the thrust of the story.

And are we really surprised? The end of the DSLR as a mainstream product was clear the moment Nikon and Canon announced their respective full-frame mirrorless mounts. Both companies have launched some DSLRs since then, but most of their efforts have been in expanding their respective ranges of mirrorless bodies and lenses ever since.

Both companies have introduced plausible mirrorless successors to their key enthusiast cameras, with the Z6 and Z7 delivering much of what the D610 and D750 did, and Canon's R6 and R5 dethroning not just the 6D series but also the iconic 5D cameras.

If that wasn't enough to show that the DSLR era was drawing to a close, Nikon's decision to introduce a mirrorless D6 competitor (and, in all likelihood, replacement) in the form of the Z9 should have made it clear. Nikon's management believes mirrorless cameras can offer more than DSLRs, even in the most technically demanding niche.

It's unlikely either Nikon or Canon will publicly announce the end of F-mount or EF-mount camera production, or associated lens production, sometime after that, but nearly four years after they both announced new lens mounts, it's quite possible that we may have seen their last DSLRs, already.

Canon has deeper pockets and a larger DSLR user base than Nikon, so we may yet see more DSLR launches, but I'd be amazed if Canon is spending its money developing anything as advanced as a 5D Mark V.

The thing it's easy to overlook is that these Japanese corporate giants aren't necessarily so huge once you drill down to the camera and lens divisions' engineering departments. Every product that gets designed comes at the cost of one that doesn't. Every minute spent working on a DSLR comes at the expense of working on technologies that move the mirrorless models forward. The same is true of lenses: both Canon and Nikon only announce a few new lenses each year, giving some insight into their available development capacity. Both companies have new lens ranges to fill out, and every new F or EF-mount lens gets in the way of progress.

These resource restrictions extend through to the factory floor. Both companies will have production lines churning out kit lenses and other popular optics, but a lot of the other ranges are likely to be made in batches, with production lines being switched back and forth between products in anticipation of demand. Again, every DSLR lens that comes out of the factory risks displacing a Z or RF-mount lens that buyers want.

At best, the market for cameras seems to be stabilizing after several years of precipitous falls. Camera makers are fighting for a small audience and don't have the luxury of offering multiple products to the same customer. In the name of survival and profits, camera makers need to focus their efforts on future buyers and sales. And the future is Z and RF-mount lenses.

It seems fair to assume that, outside the two extremes, most people care more about what a camera does than if it has a mirror and optical viewfinder. If you make a DSLR, you can sell it to those people who really want an optical finder and some of those who don't especially mind (blue dotted region). But once you've developed a new lens mount and want to compete in the fast-developing mirrorless part of the market, it makes more sense to target the red dotted region.

And, in a stagnant market, you don't want to produce both and end up competing with yourself for the middle ground.

Ultimately it comes down to the same issue as video in stills cameras. If enough of the market wants it, might use it or will tolerate it, the remaining hold-outs simply don't have enough clout to justify the creation of a model just for them. And it's even more unlikely that they have the spending power to justify the R&D, marketing and distribution/inventory costs that supporting parallel product lines demands.

Does this mean the DSLR is dead? Not just yet. The industry produced nearly twice as many mirrorless interchangeable lens cameras as it did DSLRs in the first five months of this year, but in Europe and the Americas, mirrorless was only around 20% ahead. Equally, Ricoh remains more clearly committed to DSLRs; it currently has no mirrorless models in its lineup and released its most ambitious and most capable DSLR (the Pentax K-3 III) a little over a year ago.

But the days of asking 'when will mirrorless catch up' are long past. The likes of Nikon's Z9 show that shoot speeds, autofocus capabilities and, like it or not, video, are beyond anything a DSLR could offer. So it's no surprise that Nikon is spending its time and effort on continuing to innovate in this area. It's not really news that Nikon is moving away from DSLRs, and it should be clear that the same is true of Canon.