In a word: no. And not just “they’re unsupported”, or that they have optical issues – they physically will not connect. They are deliberately keyed to be incompatible. Nikon teleconverters have a protrusion on their lens mount, which prevents any ‘standard’ Nikon-mount lens from attaching, unless that lens is missing a particular obstruction on the rear mount.
This is not unique to the Sigma 105, by any means. Nikon’s own 70-300, for example, has the exact same obstruction and also will not mount to any Nikon teleconverter (or at least, not any of the current models, of the 1.4x, 1.7x or 2x).
This is very disappointing, and an odd decision by Sigma – it was they, after all, who deliberately included the obstruction on the rear mount. The teleconverters would mount just fine otherwise – there is just enough clearance to the rear element.
In contrast, Nikon’s competing 105 macro doesn’t have the obstruction on the mount, apparently, as it’s listed by Nikon as officially supporting use with Nikon teleconverters. [I have not personally verified this]
I have heard, though haven’t verified first-hand, that the Sigma teleconverters do not have the same protrusion, and so will happily mount to any lens on which they fit (i.e. where their front element doesn’t collide with the rear element of the lens).
Autofocus is easily confused by even the faintest obstruction, anywhere in the frame.
Very strong field curvature.
Not as heavy as I expected. Still very heavy though, make no mistake.
Sorely missing VR.
Bokeh is nice, but not as magical as I’d expect.
Poor resistance to lens flare.
Doesn’t work with modern teleconverters (e.g. the 1.4x TCIII – camera body insists it’s error “FEE”, despite the aperture ring being correctly locked at f/22).
My point of comparison is primarily the Nikon AF-S 80-400 VR. That’s my go-to lens for most things, and certainly the things you’d use a 600 for.
In a nutshell, not nearly worth what it costs, even second hand and decades old. I was surprised. I assume the more modern models, particularly the current VR one, are massively better.
At a quick glance (I haven’t gone through all my test photos yet) the new Tamron 150-600 F/5-6.3 Di VC USD appears about as sharp wide open as does this Nikon 600/4. At equivalent apertures (e.g. both at f/6.3, or f/7.1) it’s a little harder to judge… in part because the Tamron has:
VC (VR in Nikon parlance).
Much more reliable and accurate autofocus.
Way less mass, and that makes it easier to get the shot to begin with. You can fairly easily hand-hold the Tamron, for example, while with the Nikon 600/4 it’s unreasonable to do so for more than ten seconds at a time. Even on a monopod the 600/4 is unwieldy, and I missed a lot of shots just struggling to get it into position and held steady.
Which altogether mean that you get many times more keeper photos with the Tamron than the Nikon, even if maybe the Nikon is maybe very slightly sharper at f/6.3. If you’re shooting wildlife, as I am, you’ll take a reliable, sharp-but-not-pixel-perfect-sharp option over a slightly sharper but unreliable one, any day.
I chose not to test as many cards as last time, when I tested the D7100. Partly because I hope that anyone spending the money on a Nikon Df is using a good quality card to go with it, and partly because the initial results made it fairly clear that performance correlates between the cameras pretty well. Also, the Df was generously on loan to me so I had to be selective about how I used my time with it.
Same test setup & method as before, in the Nikon D7100 test. The only difference is that picture area was set to FX, not DX.
At ISO 100 the average file size was right on 19.8 MiB. That rose to 25.6 MiB at ISO 800, and then to 27.4 MiB at ISO 6,400.
Points of interest
Look at that big sexy buffer! My D7100 is having severe performance anxiety after seeing this.
More seriously, note how consistent the shots are when initially buffer-bound. Much more consistent than the D7100. There’s no reason for the D7100 to drop frames and stutter when there’s buffer space available – and the Nikon Df proves it.
Props to the SanDisk Extreme 45 MB/s 16 GiB for consistently pulling ~27 + ~1.7 FPS. When you consider its reliability in contrast to the Lexar’s unreliability, and the fairly small margin between the two in performance, it’s surprisingly competitive.
Note the inconsistency of the Lexar Professional 600x 128 GiB. I double-checked my data on this to be absolutely certain, and it’s no mistake – it really does have these very noticeable glitches. (I also noticed these, audibly, when recording the shots – it’s quite obvious when it suddenly stops taking photos for a good second or so)
Overall things slow down a bit, and pretty consistently across all the cards, by a little over 10%. The Lexar Professional 600x 128 GiB appears to slow down relatively little, at just under 10%, but I suspect that’s because it simply didn’t happen to stutter as much in the ISO 800 runs.
Here I’ve re-scaled the Nikon Df‘s results to the first 10 seconds of shooting, to match the D7100’s. It also gives a better impression of just how much bigger the Df’s buffer is.
Points of interest
There’s a much bigger difference on the Nikon D7100 between the SanDisk Extreme 45 MB/s 16 GiB and the other three cards, than on the Nikon Df. This suggests that either the Df is better at utilising slower cards, or – and I think this is in fact the case – simply less demanding and less able to utilise faster cards.With the SanDisk Extreme Pro 95 MB/s 32 GiB the Df’s write rate is right about 46 MB/s, whereas the D7100’s is ~56 MB/s. It appears that the Df is limited to ~46 MB/s. I posit that the Df supports only UHS-I SDR50 or DDR50 – either way providing a theoretical bandwidth of 50 MB/s – whereas the D7100 supports UHS-I SDR104 – providing a theoretical bandwidth of 104 MB/s.
I believe the reason the Nikon D7100 doesn’t achieve 104 MB/s is because it’s actually limited by the card – a faster SD card should yield ~3 FPS, in theory (vs the ~1.9 FPS it achieves with the SanDisk Extreme Pro 95 MB/s 32 GiB). I guess now I’ll have to find such a beast… in theory something like the Transcend R95 MB/s W85 MB/s 64 GiB fits the profile. I might have to acquire one for testing…
The D7100 is “losing” in FPS only because its files are bigger. If you shoot in 1.3x crop mode you get ~15.4 MP, comparable to the Nikon Df‘s 16 MP, and thus presumably similar file sizes. I expect you’d then get noticeably higher frame rates from the D7100 than the Df. I may now go test the D7100 doing exactly that…
Unlike the Nikon D7100, this is viably a four-horse race. Because the Nikon Df seems limited by a slower SD card interface, you don’t see nearly as much benefit from the fastest cards. This makes it an interesting value proposition – the Extreme Pro 95 MB/s’s typically retail for about twice the price (per GiB) of the Extreme 45 MB/s’s, yet on the Df give you only one extra shot every two seconds (or four extra shots “in the buffer” before slowing down). i.e. a ~20% performance increase for a ~100% price increase.
It does beg the question, however: how slow can you go? Would the SanDisk Ultra now actually be attractive? I regret not testing it in the Df, in hindsight, because it’d probably put in a relatively good showing. But I’m confident in saying it’s still a noticeably slower card, and I see no reason why its horrible lack of reliability would be in any way improved in the Df, so I continue to recommend against the SanDisk Ultras, and any like “no-name-brand” or so-called “budget” SD cards.
My final rank, based primarily on performance and reliability: