As you're probably aware, Sigma just launched a US$2995 500mm f/5.6 lens that's relatively small (9", or 234mm) and light (3 pounds, or 1400g). (It also has an Arca-Swiss compatible foot, but that's another story for another day.) In some ways the new Sigma reminds me of the 400mm f/4.5: shorter in overall length due to a somewhat different optical design, and use of materials to keep it light, as well.
Until recently, Nikon had a pretty clear lead in the quality mirrorless telephoto choices. Two zooms, two 400's, two 600's, and the 800mm PF all made for a healthy set that already has everyone confused as to which one to buy (hint: if you can't articulate a specific reason, the lenses to buy are the 180-600mm f/5.6-6.3 VR or the 400mm f/4.5 VR S; anything else and you must need ridiculous reach, have perfected pixel peep, or are a bokeh buff).
Sony, meanwhile, had basically two zooms and a single 400mm and 600mm choice until recently, when they added the 300mm f/2.8GM OSS. Now with the Sigma addition, another spot in the lineup is filled, and it's a spot Nikon doesn't have covered. Okay, you could use the 500mm f/5.6E PF VR on an FTZ adapter, but people aren't buying that new to use on a Z body that I can see.
Sigma almost certainly could have made a Z-mount version of their new 500mm f/5.6, but the fact that they didn't seems to indicate that Nikon is still being protective of their mount. Perhaps even protective because they have future plans to bring their own 500mm f/5.6 PF over to the Z-mount.
The problem is simple: if you have multiple choices in another brand and more companies filling out the lens lineup, the bodies become more desirable. Sometimes I think that Nikon doesn't actually want to sell more bodies. They make system mistakes that put a ceiling on their potential. This isn't anything new, it's been a fundamental problem with Nikon for decades. Long gone are the days where Nikon actually had a full system. It might go all the way back to the F3 or F4.
Also, as usual, the problem is that Nikon isn't actually fully connected to its customers. What would its customers want?
More choice, basically, even though they already are confused by the choices they have ;~). They want to know that that little box they paid US$4000+ for (Z8, Z9) can do anything. Even if all they ever put on it is the 24-70mm f/4 S. Instead, Nikon paternalistically tends to keep saying "you can do this, and only this, because that's all we'll allow."
Imagine for a moment that the new Sigma was available for the Z-mount. You'd have a choice of two lenses at about the same price, that were the same physical length, with the shorter 400mm f/4.5 being faster and lighter than the 500mm f/5.6. Some people would pick the aperture (and Nikon reputation), some might prefer more reach at the expense of light. But both those groups would need a Nikon Z body to put it on ;~).
It's interesting to me that Nikon allowed the Tamron 150-500mm f/5-6.7 onto the mount. That gave me hope that Nikon wasn't playing too restrictive with the mount. However, it does still seem that Nikon is trying to play the middle of the protectionist road with the mount. Sony's over off on the left shoulder letting anyone play; Canon's over on the right side saying "nobody gets to do anything." The irony is that everyone can understand Sony's and Canon's positions. Nobody can understand Nikon's ;~). Another irony is that because the Sigma 500mm f/5.6 is also available in the L-mount, that makes the Panasonic full frame bodies a bit more competitive.
High tech firms seem to always want to micromanage and "own" their customer base. This works if you have a monopoly, or perhaps even an oligopoly. But it doesn't work well in a competitive market, as customers eventually become smart enough to figure out when you're placing too many restrictions on them and opt for more "open" choices. Anticompetitive behaviors then ensue, and the market doesn't grow naturally. Eventually, closed systems become disruptible.
So, a few messages to Nikon:
- Put Arca-Swiss compatible edging on your lens plates.
- Bring out a 500mm f/5.6 PF VR S in the Z-mount, stat.
- Protect your lens lineup by making all of them even better. Best products win.
- Open the Z-mount if you want to sell more cameras (and lenses ;~).
