To follow on a recent discussion (
with links to earlier PF threads), there seem to be quite a few wildlife photographers who live in the hope of Nikon releasing a 600 PF in the Z System.
This is pure speculation as there's no hint of even another Telephoto prime (yet?) on the Z System roadmap. Nevertheless, one certainty is that demand for a 600 PF will be unprecedented, especially among birders; it could well exceed demand for the 800 PF!
One possibility is Nikon designers decide to "scale down" the 800 f6.3S PF (385mm long) - yet keep the 128mm window in a shorter 600 f4.8S. Or they may decide (have finalized) on a 600 f5.6S PF. This will follow up the existing 2018 patent.
A Z 600 PF should weigh well under 2kg, even as a f4.8S prime: being shorter overall. This suggests dimensions of 112mm x 314mm (based on the F mount patent of ~283.5mm length (less 46.5mm throat depth, see Nikon's 2018
patent). Note the patent specifies a 500 f5.6 PF of 28 cm to the focus plane, which is realized in its final length of 237mm (+ 46.5mm throat depth)
Besides being 10cm shorter than the 800 PF, another reason for a lighter 600 PF is a prime has fewer glass elements than the lighter tele zooms, pertinently the 180-600 f5.6/6.3. Whatever eventuates, if ever, in a 600 PF, we can expect its final specifications will set an unprecedented benchmark for a light, short supertelephoto prime, compared against any of the super tele zooms, let alone the exotic primes.
Another lesson from the rumours (that kicked off in September 2021) until final launch of the 800 PF is how its official price was
widely overestimated, across the internet. The predictions by some merchants of gloom even invoked the exotic price of the 800 f5.6E FL.... overestimating the RRP by several thousands of $$ in some cases
![Big grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
While window diameter is the dominant factor in price of a telephoto, (see
comparisons by Photography Life), avoidance of fluorite elements and/or an Internal Teleconverter also reduce production costs.