I could have written “do you need better than S” in the headline, but I’m going to tackle this topic more narrowly for the moment.
The underlying questions are (1) just how good are the S-line lenses? and (2) what happens if we get a 61mp, 67mp, or even 100mp camera?
The first question is easy to answer. I’ve now used all the S-line lenses except for the nearly-impossible-to-get 600mm f/4 TC VR S. I’ve used them all on 45mp cameras, and most in serious work situations (event, sports, wildlife, some landscape).
The answer is that I have to look way too much at pixels to find anything I’d consider a “fault" with these lenses other than perhaps vignetting, which is something I actually tend to add to my images, not subtract. Plus, I have to look at the extremes (e.g. corners) to find those faults, and often only see them only wide open, if at all.
I get questions about the two 50mm S-line lenses all the time (“is the f/1.2 worth it?”). Yes, the f/1.2 is better at the same aperture as the f/1.8, but the f/1.8 is already at such a high level I have to wonder why I’d want the f/1.2. I’m tempted to write that the f/1.8 is Very Near Otus while the f/1.2 is Significantly Past Otus in capability. And I wasn’t using those expensive Zeiss Otus lenses in the first place!
I’m just not worried about putting any S-line lens on my Z7 II or Z9 body. I’m not going to dislike the results. If I get into truly serious pixel peeping I have tools available that fix what little I can find that might be sub-optimal. Generally, my biggest issue with the S-line lenses is using them at f/11 of smaller aperture, where diffraction is stealing too much from their optical greatness to ignore.
Which brings us to the second question: will the S-line survive likely pixel increases of the future, or do we need an S-squared-line?
I can’t say for sure about that, because as far as you know I don’t have a 100mp camera. However, I have two thoughts about that.
First, Nikon knows what’s coming in terms of pixels. I sincerely doubt that they’d have 19 lenses designated S-line at this point if they felt that those wouldn’t stand a couple rounds of image sensor bumps.
Second, everything I measure in the current S-line lenses at 45mp tells me that their optics are performing at extremely high standards, and that it might actually be the image sensor or even microlenses or something else that’s holding them back from everything they could resolve. Heck, are our current autofocus systems even up to the job of positioning the focus plane perfectly for 100mp?
So my current response to the headline question is a clear “no.” I’m happy with the S-line lenses. Very happy. Not a dud in the bunch, though the 14-30mm f/4 S is somewhat closer to where I’d draw the line than are all of the others.
The corollary, of course, is “Do I need better than the non-S-line lenses?” Here we find the recent Tamrikon f/2.8 zooms and the muffins. I think it should be clear so far that my answer that those are also good lenses, but they do tend to have clear liabilities the S-line lenses don’t, particularly as you move further from the center axis and into the corners. They’re still really good lenses, it’s just that I can see liabilities as I work with the pixel data generated using them. Again, typically as I near the corners. That said, the Tamrikon 17-28mm f/2.8 is closer to S-line than the others, which was a bit of a pleasant surprise.
Bonus: If you’re still a DSLR-only user, let me frame this discussion a bit differently. If you’re primarily using 20-100mm optics, the mirrorless S-line user is getting better pixel data than you are. I’d even say that if you’re using a Zeiss Otus on your DSLR, as you’re manually focusing that lens and the manual focus tools on the Z cameras are simply better and more accurate. Plus Sensor VR, since you’re probably not using a tripod ;~).
Below 20mm we have a lot to talk about, and I believe that even with the two 14mm-x S-line zooms the DSLR user may find some advantages. Personally, I use the 19mm PC-E on my Z7 II for landscape these days, but I don’t like the extra adapter involved.
Above 100mm, and Nikon’s telephoto options with a fixed maximum aperture have always been superb, even back into the film SLR days. The advantage the S-line telephotos are bringing isn’t necessarily optical, but in terms of size, weight, and handling.
