The Z 600mm f4 TC VR S is Nikon’s fourth long telephoto prime lens for Z-mount aimed at professional sports and wild-life photographers. It has a large f4.0 focal ratio and comes with an integrated 1.4x teleconverter (TC) – and a price to match. The TC can be activated with a switch and converts the lens into an 840mm f5.6 lens – a feature that neither Sony nor Canon offer for their respective super-telephoto mirrorless primes to date. The new lens is also compatible with Nikon’s “external” Z TC-1.4x and TC-2.0x. This allows it to be converted into a 1200mm f8.0 or even 1680mm f11 lens.
Apart from the usual features like optical image stabilization, focus limiter, programmable function buttons, and control ring, the new lens offers the same additional features as Nikon’s Z 400mm f2.8 TC VR S: There’s an integrated filter slot to drop in standard 46mm filters, a memory-set button to save focus distances, and the focus ring can be switched from non-linear to linear response with a choice of different rotation angles (on a Z9). It also offers a function (Fn) ring to recall the last-saved focus position, plus it has Nikon’s newest “meso amorphous” anti-reflex coating in addition to ARNEO coating to further increase contrast in challenging contra-light situations. Only the OLED display is missing. Nikon also managed to reduce the weight of the lens by over 0.5kg over its predecessor, the Nikon AF-S 600mm f4E FL ED VR, which was introduced in 2015 and still can be used via FTZ adapter on Nikon’s Z cameras. So, weight-wise Nikon has now almost caught up with Sony’s and Canon’s 600mm f4.0 lenses for mirrorless bodies – but those don’t carry an integrated teleconverter with them.
The Nikon Z 600mm f4 TC VR S is made in Japan and costs 17249 EUR / 15497 USD / 15499 GBP. This seems like an extraordinarily high price, but Sony’s and Canon’s own versions are also all in five-figures and come without a built-in TC. If you’re interested in what Sony and Canon have on offer head over to Gordon’s Sony FE 600mm f4 GM OSS review so far or Canon RF 400mm f2.8L RF 600mm f4L review.
Facts and features
Let’s compare the Nikon Z 600mm f4 TC VR S (“Z 600 TC” for short) to the Nikon AF-S 600mm f4E FL ED VR (“F-Nikkor”), Nikon Z 400mm f2.8 TC VR S (“Z 400 TC”), and Nikon Z 800mm f6.3 VR S (“Z 800”). I’ve also added some information on Sony’s FE 600mm f4 GM OSS and Canon’s RF 600mm f4 L IS USM just to give you an idea where the competition stands. As usual I’ve rated the features with a [+] (or [++]), when it’s better than average or even state of the art, a  if it’s standard or just average, and [-] if there’s a disadvantage.
The first thing which catches the eye is the apparent similarity of the Z 600 TC and the Z 400 TC from the mount up to the segment where the 4 function buttons (L-Fn2) are located. So, everyone who uses the Z 400 TC will feel immediately at home handling the Z 600 TC. [+]
Size (diameter x length): 165 x 437mm (6.5 x 17.2in.). The lens hood probably adds 127mm. The F-Nikkor is 166 x 432 mm + lens hood. Add 30mm for the FTZ adapter to use it on a Nikon Z camera. The Z 400 TC is 156 x 380mm + 127mm lens hood. Add 19mm resp. 33mm for the TC-1.4x or TC-2.0x. The Z 800 is 140 x 385mm + 126mm lens hood. The Sony is 164 x 449mm, the Canon RF is 168 x 472mm. So, although the Z 600 TC is the longest Z-Nikkor (so far) it is a bit shorter than the competition. 
Weight: 3260g (7.2 lb.) including tripod foot plus around 280g for the lens hood. The F-Nikkor is 3810 g + lens hood. Add another 133g for the FTZ adapter to use it on a Nikon Z camera. The Z 400 TC is 2936g + 232g lens hood. Add 220g for the external TC-1.4x to get focal lengths comparable to the Z 600 TC. The Z 800 is only 2382g + 241g lens hood. The Sony is 3040g, the Canon RF is 3090g – both without lens hood. 
Optics: 19 elements in 16 groups including 4 special dispersion elements and two fluorite lenses but no aspherical element. The built-in 1.4x TC (marked in the image above) adds 7 elements in 4 groups. The lens has the newest “meso amorphous” anti-reflective coating in addition to Nikon’s ARNEO-coating to reduce flare, glare and ghosting plus fluorine-coating on the front element to repel water, dust, and dirt and make cleaning easier. The F-Nikkor has 16 elements in 12 groups with two fluorite elements. The Z 400 TC has a total of 25 elements in 19 groups when the internal TC is switched on, the external TC-1.4x adds 6 elements, the TC-2.0x 8. The Canon RF has 17 elements in 13 groups, the Sony EF 24 elements in 18 groups. [+]
Minimum object distance is 4.3m (7.9ft.) with a working distance of around 3.9m and a maximum magnification of 1:7.1 which is not much but similar to what the F-Nikkor, Sony FE, and Canon RF offer. A magnification of 1:10 should be achieved at around 6m object distance. Using the built-in TC increases maximum magnification to 1:5.0 without changing the working distance. This is a bit better than the 1:5.8 which the Z 800 achieves. The Z 400 TC achieves a maximum magnification of 1:5.6 at 2m working distance or 1:3.9 when the built-in TC is switched on. [+]
Image stabilization: All three Z-Nikkors offer optical stabilization (VR) which works in conjunction with the body-based stabilization on Nikon’s full-frame Z cameras to achieve a claimed 5 stops of stabilization over 5 axes for the Z 600 TC. For the F-Nikkor the Z cameras only add roll correction to pitch and yaw correction from the lens’s VR. On a Nikon Z9 the Z 600 TC enjoys an additional benefit from “Synchro-VR”. [+]
Filter-thread: The Z 600 TC has an integrated slot for 46mm standard filters and Nikon offers a slip-in circular polarizing filter as an additional accessory which can be easily rotated (399 EUR). The F-Nikkor has a slot for 40.5mm filters. [+]
Autofocus: Yes with built-in AF drive which uses a voice coil motor (VCM) and optical encoder, just like the Z 400 TC. This AF drive technology seems to be the reason for Nikon’s health warning against strong magnetic fields. Manual-focus override is by simply turning the dedicated focus ring at the middle of the lens. On Nikon Z cameras introduced October 2020 or later you can reverse focus direction. The focus ring has the usual variable gearing (like all AF Z-Nikkors so far) which allows for very precise manual focus when turned slowly and can be switched to linear response with a choice of different rotation angles – but only on a Nikon Z9. Focus on the F-Nikkor works differently as it has a direct linear mechanical coupling between the focus ring and the focus action. [+]
Display: No, the Nikon Z 600mm f4 TC VR S (just like the other Z-Nikkors in this comparison) does not feature an OLED display. The F-Nikkor sports the usual distance and dof indicators on the focus ring. 
Additional functions: There are 4 function buttons at the front (L-Fn2) and an additional L-Fn button behind the focus ring on the lens which can be assigned different functions like AE/AF lock. Like the Z 400 TC the Z 600 TC offers a function ring in addition to the control ring all Z-Nikkors offer: it works in conjunction with the memory set button near the TC switch to recall saved focus positions by simply turning it a bit to the left or right. All lenses in this comparison also sport a focus-limiter which in case of the Z 600 TC prevents the lens to search focus closer than 10m (33ft.). [+]
Aperture ring: The lens has the usual slim multi-function control ring which on all three Z-Nikkors is located in front of the focus ring. The control ring can be assigned to operate the aperture (which is the default), exposure compensation, or ISO sensitivity – or simply switched off. The F-Nikkor has no dedicated aperture ring. [+]
Lens profile: All four Nikkor lenses come with a lens profile which can be controlled from the camera. Vignette control offers the usual options of High, Normal, Low and Off. Diffraction compensation and Auto distortion control can be activated or deactivated. [+]
All lenses in this comparison cover full frame/FX or smaller sensors. [+]
Price: 17249 EUR (incl. 19% VAT) / 15497 USD / 15499 GBP. The Nikon AF-S 600mm f4E FL ED VR currently sells for 13000 EUR / 12300 USD / 13000 GBP, the Sony FE 600mm f4 GM OSS is 14000 EUR / 13000 USD / 12000 GBP, the Canon RF 600mm f4 L IS USM is 14000 EUR / 13000 USD / 13400 GBP. 
Use with teleconverters: The Z 600 TC like the Z 400 TC has a 1.4x teleconverter already built in which can simply be activated with a switch. The TC switch can be locked, and Nikon advises to do so to prevent unintended operation. But all three Z-Nikkors in this comparison can also be used with Nikon’s teleconverters for Z-mount: The Z TC-1.4x for 549 EUR (incl. 19% VAT) / 547 USD / 549 GBP and Z TC-2.0x for 660 EUR / 597 USD / 580 GBP. Keep in mind though that the Z TCs cannot be used with the FTZ adapter. [++]
Accessories: The Z 600 TC comes with a well-padded case which offers good protection for lens and is the same for the Z 400 TC and Z800. But I doubt that you can stow the Z 600 TC away with camera attached. It has two straps on the outside to carry a tripod plus a strap inside to secure the lens from inadvertently falling out when you open the case. It also has a grip on top and a shoulder-strap to carry it like a backpack. The lens comes with a carbon lens hood which is locked in place with a screw plus is reversible for transport. It has a rubberized front- and back-end plus it’s coated like black velvet on the inside to reduce reflexes. When you lock the lens hood in place it bends slightly out of shape. Using the lens hood (either normally or in reverse) is the only way to attach the slip-on front lens cover. [+]
Tripod mount: The Z 600 TC has the same tripod collar as the Z 400 TC and Z 800. The ring rotates smoothly – when unlocked – and has little play but there are no click-stops at 90 degrees. The tripod foot is firmly attached to the collar with four screws which can be removed with an Allen key. The foot weighs 121g. The whole construction feels very solid once the attachment screw is tightly locked. Under the rubber cap of the screw is a security slot for attaching an anti-theft cable. There are also two eyelets on the tripod collar to attach the included strap to – never use the strap on the camera to carry such a heavy load. Unfortunately Nikon missed out (again) to make the foot Arca-Swiss compatible. The tripod foot has two mounting threads: one 1/4″ and one 3/8″. The latter can be used e. g. for mounting the foot directly on a half ball – which should give you the most rigid connection to a tripod. 
Sealing: yes. All lenses in this comparison have a rubber grommet at the lens-mount plus further special weather-sealing throughout the construction. [+]
At a score of 0[-]/5/14[+] the Nikon Z 600mm f4 TC VR S turns out to be a very well featured lens with its preeminent and unique feature of a built-in 1.4x teleconverter. It weighs considerably less than its predecessor and has the new and improved coating to increase contrast in addition to ARNEO anti-reflex coating. It might miss an OLED display and its price is higher than the Canon and Sony 600mm f4 primes but remember the Nikon has the built-in 1.4x TC, essentially giving you two lenses for the price and weight of one: a 600mm f4 and a 840mm f5.6.
Sharpness and contrast
Let’s have a look at the theoretical performance of the Nikon Z 600mm f4 TC VR S and compare it to its predecessor plus the Z 400mm f2.8 TC VR S and Z 800mm f6.3 VR S:
These MTF charts show the computed lens-performance of lenses wide open at infinity without influence of diffraction at 10 line-pairs/mm (red) and 30 lp/mm (blue). Higher values are better (more contrast) and the closer the dotted and solid lines are together the less contrast dependents on the orientation of the test-pattern (less astigmatism). The x-axis displays the distance from the optical axis (=center of the sensor) in mm.
From the charts the Z 600mm f4 TC VR S shows extremely high overall contrast and resolution of fine details. It looks a bit better than its predecessor and clearly better than the Z 400mm f2.8 TC VR S with its internal TC switched on (at 560mm f4.0). Activating the build-in 1.4x teleconverter on the Z 600mm f4 TC VR S still delivers very good contrast/resolution at 840mm f5.6. But the Z 800mm f6.3 VR S even looks better – at least on paper.
Only real-life tests will show whether the relatively small differences in the MTF-charts have any relevance. But judging from the excellent performance of the Z 400mm f2.8 TC VR S and the MTF-charts above I’m pretty sure that Nikon’s Z 600mm f4 TC VR S will be another winner in their growing arsenal of long telephoto lenses. Check back for my full review as soon as the lens becomes available.Check prices on the Nikon Z 600mm f4 TC VR S at B&H, Adorama, WEX UK or Calumet.de. Alternatively get yourself a copy of my In Camera book, an official Cameralabs T-shirt or mug, or treat me to a coffee! Thanks!