Will there be a D7?

I think a 120-300/2.8 PF for Z-mount would be interesting - especially if the weight would be similar to that of the 70-200/2.8.

How should this work, glass is heavy, the larger the more

glass is heavy

Yes, but PF elements are about 1/2 the weight compared to those of a similar overall focal length.

How should this work, glass is heavy, the larger the more

Yes, but PF elements are about 1/2 the weight compared to those of a similar overall focal length.

I was overly enthusiastic in my post - expecting a more than half reduction in weight (from 7lbs to a little over 3lbs) is indeed unrealistic - but a reduction by about maybe 1-1 1/2 lbs could be expected (especially if the overall length of the lens is reduced as well). So far though, there's no real world experience with PF technology in zooms (Canon released a variable 70-300 DO a decade or so ago; it was small but not lighter than a conventional 70-300). A direct comparison between the AF-S 300/4 and the AF-S 300/4 PF shows a reduction in weight by about 1lbs and a reduction in size from 70-200/2.8 dimensions to 24-70/2.8 dimensions.

the deal I got on a brand new Tokina AT-X Pro 14-20mm f/2 for about $400 (I think the original price was over twice that)

Original price IIRC was $899; it's current price is $379 (with a discount from the MSRP of $499). Makes me wonder what happened? Sigma's 18-35/1.8 has not seen a similar drop in price.

opportunity to pick up F-mount bargains which will breath some new life into my "old" cameras

I am quite certain that I have purchase my last F-mount lens with the 500PF in 2019.

I'm fine with my NIKKOR AF-S DX 16-85mm f/3.5-5.8G VR that weighs less and cost me about $200)

Trade it for a 16-80/2.8-4 if you can find a good deal on one - you won't regret it.

NIKKOR 24-120mm f/4G VR in good condition for about $400

In the past, occasionally, the lens was available refurbished for around $530; I got (but returned) an excellent copy from keh in 2017 for $572.

I am quite certain that I have purchase my last F-mount lens with the 500PF in 2019.

I still remember the 'Patent' for the Nikon 600mm PF. I wonder where that went?

Nikon 600mm PF. I wonder where that went?

Maybe that will be the first PF to be released in Z-mount?

At f/5.6 it’ll be quite expensive ($5.5k-$6k at best; more like $7k+); less so if f/6.3 ($4.5k-$5k?).

The same patent also included a 400/5.6 PF.

I am quite certain that I have purchase my last F-mount lens with the 500PF in 2019.

Most likely, the same is true for me. In January 2019, I bought the 500mm PF and a D850 body, both ahead of a major February 2019 trip to Antarctica. I also brought a Z6 on that trip and used it a lot for both landscape and video. I was very pleased with the ability to quickly switch between still capture and video, both using the EVF.

Unless there is some major catastrophe (fire, theft ...) such that I lose a lot of the F-mount bodies and lenses I am still using, it is very unlikely that I'll buy any more F-mount products. In fact, if high-end Z bodies and super teles are available later on in 2021, I'll simply replace with those Z products. (Or just in case Nikon Z doesn't come through, I can always migrate to mirrorless

in another brand.)

Concerning Nikon's PF lens patents, as far as I know there were f5.6 patents for 400mm, 500mm, and 600mm. I think the 500mm/f5.6 PF is the sweet spot. Any handholdable 600mm lens should be max f6.3 to keep the size and weight down. A 400mm/f5.6 PF is too slow. For a 400mm, I think Canon has it right to make a 400mm/f4 DO lens, which also gives you the option to add a 1.4x TC to make it a 560mm/f5.6, but Canon's 400mm/f4 DO lens is close to $7000. That is a lot more expensive than Nikon's 500mm/f5.6 PF.

I think a 120-300/2.8 PF for Z-mount would be interesting - especially if the weight would be similar to that of the 70-200/2.8. And the price more reasonable than the current $10k.

Is it physically possible to have a Phased Fresnel zoom lens? Or is the focal length of a Fresnel lens fixed?

Is it physically possible to have a Phased Fresnel zoom lens? Or is the focal length of a Fresnel lens fixed?

This is where the terminology of 'LENS' is ambiguous.

A PF element, ie a single chunk of glass, is much the same as a conventional element, but to get the same focal length has about 1/2 the mass.

So, a Phase Fresnel Nikkor usually only has one of the front elements ground to be a fresnel lens, all the others are 'normal', so no reason a zoom can't be made. However, making large PF elements seems to be an expensive game with a high failure rate.

Is it physically possible to have a Phased Fresnel zoom lens?

Nikon must think so - they filed patents for a 70-300 lens for their Series 1 cameras and there's also a patent for an FX 24-70/2.8 with PF technology. Obviously, neither lens has made it into production though. And then there is/was Canon's 70-300 DO lens.

For a 400mm, I think Canon has it right to make a 400mm/f4 DO lens, which also gives you the option to add a 1.4x TC to make it a 560mm/f5.6, but Canon's 400mm/f4 DO lens is close to $7000.

From what I've heard the 1st version of the 400/4 DO did not take a TC well; the 2nd one supposedly did better with it. Price, the fact that I don't seem to get along with Canon camera UI all that well, and 400mm being a tad short kept me from going for the 1st version back then; the 2nd one as I recall was quite a bit more expensive. I did recommend the 1st version to a Canon shooter, and she was very happy with her purchase.

Nikon coming out with the PF lenses was game-changing for me. The 300PF is so small and light that it almost always is in the bag - much unlike it's non-PF predecessor. And the light weight of the 500PF makes it a joy to use and poses no issues during long walks with the camera in hand (actually the lens foot).

I think the 500mm/f5.6 PF is the sweet spot.

I think so too.

A 400mm/f5.6 PF is too slow.

Nikon could make it an f/4.5 or f/5 and still keep the cost in check.

a Phase Fresnel Nikkor usually only has one of the front elements ground to be a fresnel lens

For both PF lenses currently in existence, it appears to be the innermost lens of the front group. So yes, it's a large one. Canon's DO technology appears to be technically different - their DO element consist of two lenses with a small gap in case of the 1st 400/4 version and gapless in the 2nd. The dual-element has the same size as the front element in the 1st version but is smaller and sits farther back for the 2nd version.

Nikon must think so - they filed patents for a 70-300 lens for their Series 1 cameras and there's also a patent for an FX 24-70/2.8 with PF technology. Obviously, neither lens has made it into production though. And then there is/was Canon's 70-300 DO lens.

Canon's 70-300mm DO lens is a PF zoom, although Canon call them Diffractive Optics (DO) instead of Phase Fresnel lenses:

Canon U.S.A., Inc. | EF 70-300mm f/4.5-5.6 DO IS USM

Once again, Canon DO is not cheap. That 70-300mm/f4.5-5.6 DO is over $1000, about twice as expensive as conventional 70-300mm/f5.6 lenses.

400mm is a bit like 400yds in athletics.....:)

Is it supposed to be a super sprint ie 2.8..

or a very fast jog, ie 5.6.

400mm f4 PF seems to be a happy in-between point. Didn't seem to work for Canon, but who knows?

Why is a 400/5.6 PF too slow and 500/5.6 is not? A 400/4.5 has the same size front element as the 500/5.6 so wouldn't be any cheaper or lighter, only a bit shorter.

I think there is a useful spot for a 400/5.6 PF lens. Such a lens would be significantly lighter and more compact than the 80-400 zoom, and probably cheaper. It should have better optical quality - zooms tend to have higher vignetting and distortion, and are usually weak at the tele end. It would give more reach than the 300/4 PF and better quality than the 300PF + TC, in a lens which is only a little longer and heavier. Plus it would be much smaller and more affordable than the 500PF, so would be within the reach of many more photographers. Combined with a 1.4x TC it would give a 560/8 lens, which seem more attractive to me than the Canon 600/11 STM lens. If it had decent close focus ability, it would be a very useful lens.

Such a lens would be significantly lighter and more compact than the 80-400 zoom, and probably cheaper. It should have better optical quality

All true - yet Canon never updated their 400/5.6L lens - not even to incorporate IS. Nikon never even ported their manual focus 400/5.6 over to AF, much less AF-S - probably expecting everyone to either get a 80-400 zoom or use the 300/4 with a TC-14E. Above we touched on the lack of a 300/2.8 lens for any mirrorless lens mount; the same can be said for a 400/5.6 - though the customer for either would certainly be different.

I'd expect a 400/5.6 PF to cost about the same as a 300/4 PF - currently $2k. Not that different from the cost of a 80/100-400 lens. If f/4.5, the cost can be expected to be equal to the 500PF - currently $3.6k.

I think there is a useful spot for a 400/5.6 PF lens.

Why bother, a 400mm PF 5.6 isn't going to be so much lighter than a newer 400mm 5.6?

Interestingly (?) the 500mm 5.6 PF is the same weight as the 400mm 5.6 AI.

Why is a 400/5.6 PF too slow and 500/5.6 is not? A 400/4.5 has the same size front element as the 500/5.6 so wouldn't be any cheaper or lighter, only a bit shorter.

The main advantage for PF is hand-holdability and portability. The 500mm/f5.6 PF happens to be an excellent tradeoff between reach, weight, size, and also cost. I use mine on both FX and DX bodies. On DX, the reach for 500mm is quite substantial. Anything longer will be very difficult to locate your subject in the viewfinder while hand holding.

I think 400mm is often not long enough for birds. Therefore a 400mm/f5.6 will always lose out to the 500mm/f5.6. Additionally, we can already add a 1.4x TC to the 300mm/f4 PF and make it a 420mm/f5.6. However, another stop in the 400mm/f4 will give it more low-light capability and the option to add a 1.4x TC and still maintain f5.6.

IMO, both Canon and Nikon got it right with 400mm/f4 and 500mm/f5.6 PF/DO lenses. I have friends with the 2nd generation of the Canon 400mm/f4 DO. Its 100mm front element is certainly not small, but it is relatively short and is handholdable.

Canon's 70-300mm DO lens is a PF zoom, although Canon call them Diffractive Optics (DO) instead of Phase Fresnel lenses:

 

Canon U.S.A., Inc. | EF 70-300mm f/4.5-5.6 DO IS USM

 

Once again, Canon DO is not cheap. That 70-300mm/f4.5-5.6 DO is over $1000, about twice as expensive as conventional 70-300mm/f5.6 lenses.

The reviews of the lens in the link you posted are less than stellar!

With regards to potential advantages of a 400/5.6 PF prime, note how much faster the 500/5.6 PF focuses compared to the 200-500/5.6. The 500 PF is also sharper than either the 80-400 or 200-500 at their longest setting wide open. A 400/5.6 PF could offer similar advantages. I think a 400/5.6 PF could be very small indeed, and for some applications (such as big outdoor concerts) I think it could be quite useful. I get it that the 500/5.6 PF is more useful for bird photography and it's still very portable. I could combine a 70-200/2.8 and 400/5.6 where I've used the 300/4 which is a little short for large stage close-ups, but the 500 is a little long (it can work, but the gap between 200 mm and 500 mm is quite big). I get it that the 300/4 can be combined with the 1.4X TC but I haven't been happy with this combination for longer distances (it is quite good for close-ups of small subjects).

For every focal length there is someone who has an application for it. ;-) However, I understand that a single manufacturer may have to do their best efforts on the most common needs (70-200/2.8 is certainly among those) and then choose where the "special lenses" are added from time to time.

I do agree that the 500/5.6 is a very useful lens, I've had a lot of fun with it the past 1.5 years and I've been able to try my toes in wildlife photography without carrying a heavy bag.

I finally purchased the 300/2.8 as I had been waiting for an FL version and put off this purchase for some time. I figured in the current situation Nikon may not make the FL version in F mount so I might as well buy the current one. I can't say Nikon neglected this lens; there are no fewer than six autofocus versions of the 300/2.8.

I finally purchased the 300/2.8 as I had been waiting for an FL version and put off this purchase for some time. I figured in the current situation Nikon may not make the FL version in F mount so I might as well buy the current one. I can't say Nikon neglected this lens; there are no fewer than six autofocus versions of the 300/2.8.

Likewise!

I ended up with the first VR version. It does sound a bit rough when the VR activates, but the image stabilises OK.... Not rock steady like the 200-500mm does but it's OK.

AFAIK, the optics are the same between VR and VRII. Whether the VR prisms/elements are different, I don't know.

I tried it as a bug chaser this Spring, and although it's notably heavier (!) than the 200-500mm and maybe more front heavy, it's way sharper, so big crops are much more achievable, either from the D850 or D500.

I'll try it with the TC1.4E II, when I can find it again;)... I hope I didn't lend it to someone:eek:

Whether the VR prisms/elements are different, I don't know.

From what I've read, a one-stop more efficient VR was the main/only? change from the 1st VR version of the lens to the 2nd.

it's way sharper

Not that I doubt that (published (and hence calculated and not actually measured) MTF data don't show a major difference until about half way through the frame) - but could this also/just be due to higher accuracy in focusing because of the shallower DOF at f/2.8 vs f/5.6? In other words, are "narrow" misses more likely with at f/5.6 than at f/2.8? The weaker AF motor in the 200-500 may also play a role in focus accuracy (it certainly does in speed).

The weaker AF motor in the 200-500 may also play a role in focus accuracy (it certainly does in speed).

Yes, I think that's the key for a moving target or photographer! The AF can keep up with me swaying gently back and fro waiting for the critter to settle or at least hover i space...;)

From what I've read, a one-stop more efficient VR was the main/only? change from the 1st VR version of the lens to the 2nd.

The second VR version also has an A/M switch option which gives priority to autofocus if the photographer accidentally turns the focus ring a bit. Optically the lenses are the same. What may be more significant is that the VR II lens is a current lens and some spare parts may be unavailable for the first VR version in case it needs repair. Of course, how many spares are available for the current version is unknown but generally parts should be available for several years after manufacturing ends (but not indefinitely).

The reviews of the lens in the link you posted are less than stellar!

You noticed that is a Canon lens, right? :D I own exactly zero Canon lenses; it is merely an example that PF zooms are possible.

Seriously, Canon makes a lot of great lenses, but their first two attempts of DO lenses have mixed reviews. Apparently the 2nd generation of the 400mm/f4 DO is quite good. In that sense I am glad that Nikon waited until the technology is more mature before introducing any PF lenses.

Original price IIRC [of the Tokina AT-X Pro 14-20mm f/2] was $899; it's current price is $379 (with a discount from the MSRP of $499). Makes me wonder what happened? Sigma's 18-35/1.8 has not seen a similar drop in price.

Might be excess production meets reduced demand and Sigma might have better anticipated that. It might also be that 18-35mm is more in the wide to normal range and is a 2x zoom versus the wide to super wide range that covers 1.5x and doesn't actually go wide enough for some people (my take on that last part is most people think they "need" to go wider than they probably should; about the only time I'm feeling constrained by 14mm on DX is when I'm in Yosemite Valley).

Trade it [my AF-S DX NIKKOR 16-85mm f/3.5-5.6G VR] for a 16-80/2.8-4 if you can find a good deal on one - you won't regret it.

I'm not sure about the utility of this sort of lens for me. I've always been a little reticent about toting around a "walk-around" zoom for reasons I can't quite put my finger on, so while I'll slap the zoom I have on my D500 when I'm walking around I don't think I can justify spending another $400 for an upgrade to it (I would lose some money selling my current lens, which makes only spending an extra $400 somewhat optimistic unless I get a beat-up copy).

I'm thinking about the Sigma 50-100mm f/1.8 because that lens, like the Tokina 14-20mm, gets me capabilities on my D500 that would make it comparable to what I can do on my D800.