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The FTZ Adapter


ShunCheung

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This is my understanding of how the FTZ adapter works after using it for merely a few days. For a while I wasn't sure whether my FTZ is working properly, but apparently this is how it is supposed to work. Other members who have more experience with the FTZ, please provide your input and correct any errors I may have. Obviously I am still learning about it and my understanding may evolve.

 

At its introduction, Nikon has only three Z mount lenses for their new mirrorless system, and given that Nikon has produced over 100 million F-mount lenses in the past six decades, plus many third-party F-mount lenses, it is critical to adapt them onto the Z system, hence the FTZ (F-mount-To-Z-mount) adapter.

 

Besides the mount itself that locks an F-mount lens onto the FTZ, the adapter has two mechanical connections on the F side: (1) the mechanical aperture control lever that pushes the spring loaded aperture control on the F-mount lenses, until Nikon introduced E lenses about a decade ago, and (2) the EE Servo Coupling Post that detects whether the aperture ring on a lens with CPU (including almost all AF, AF-D and some early AF-S lenses, pre G, such as the 17-35mm/f2.8 AF-S shown below) is set to its minimum aperture. (As far as I know there is only one AF-D lens that is G without an aperture ring, the 10.5mm/f2.8 DX fisheye; it is a G lens but not AF-S.)

 

Fortunately I have many F-mount from various vintage to check the FTZ out with. I bought my very first Nikkor lens in 1977 at the very beginning of the AI (auto indexing) era, a 43-86mm/f3.5 AI. Hence I have no pre-AI lenses. See the image at the bottom of this post of some of the lenses I have tried on the FTZ. Besides those, I have used other Nikon AF-S G and E lenses with the FTZ. The Sigma 35mm/f1.4 Art works as an AF-S G lens.

 

When I mount the 35mm/f1.4 AI-S on the FTZ, the mechanical aperture control does not push the aperture to wide open. Instead, the aperture opens to whatever the aperture ring is set to. If you set the aperture to f11, the Z6 would compose and meter at f11. Hence the aperture doesn't need to close further down when you press the shutter release.

 

For any AF lens with an aperture ring, including AF, AF-D, and AF-S (I don't have any AF-I lens, but they should work the same way as AF-S lenses with an aperture ring), you must set the aperture to the minimum and preferably lock it there. Otherwise, the EE Servo Coupling Post would detect that and give you the FEE error. Since there is no aperture follower tab on the FTZ, you don't get the option to use the aperture ring to control the aperture; you must use the sub-command dial (or main command dial if you reverse main/sub).

 

With G lenses and most E lenses, since there is no aperture ring, you just use the sub-command dial to control the aperture, and the EE Servo Coupling Post plays no role. (There are some E lenses such as the PC-E lenses that have an aperture ring.)

 

With any AF, AF-D, and AF-S lenses on the FTZ, as well as native Z-mount lenses directly on the Z camera, during composition, when you control the aperture with the sub-command dial, the lens' aperture actually closes down from the maximum to f5.6, but when you change the setting to something smaller such as f6.3, f8, f11, the aperture on the lens would not close further down below f5.6, during composition and metering. Hence we are using partial stop-down composition and metering. If your aperture setting is at f5.6 or above, the Z6 composes and metering at the set aperture, but it would not go below. I personally don't have any lens whose maximum aperture is slower than f5.6. If you use one of those zooms that is wide open at f6.3 on the long end, I assume you would be composing and metering at f6.3 all the time.

 

One final issue, when mounted onto a Z6 or Z7, the bottom of the FTZ stick out below the bottom of the camera body. See the top right image below. I am sure that is an annoying "feature," especially when you attach a wider bottom QR plate to the camera body.

 

Again, I am just learning how all of these work. I am sure there is a lot more to discover.

 

FTZ_1474a.jpg.5efa9ee99816d6c1166d431c10353cf9.jpg

 

Lenses_1477.thumb.jpg.afd0961c7fedeba43fda554efe64f93c.jpg

 

F-mount lenses from different vintage, from left: 35mm/f1.4 AI-S, 105mm/f2.8 AF macro, pre-D, 24mm/f2.8 AF-D, 17-35mm/f2.8 AF-S with aperture ring, and Sigma 35mm/f1.4 Art in F mount

Edited by ShunCheung
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Ah, yes the FTZ > Z body offset.

 

i guess they tried to make it 'level' but couldn't get the aperture motor housing thin enough.

 

If you mount a QR plate to the FTZ how big is the gap? Looks to be about CF card size.

 

I can foresee a stepped QR plate with 2 screws or a nicely designed spacer.

 

Obviously any lens with it's own foot is the right way to mount it to minimise stress.

 

With something like the 14-24MM 2.8 (@ 970gm or a bit over 2 lbs), the FTZ would appreciate a shared QR plate so all the weight isn't trying to pull the mount plate off.

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Late Edit.

especially when you attach a wider bottom QR plate to the camera body

 

Maybe you're not supposed to? The QR plate goes on the FTZ, not the body?

 

Might need an L Plate for the FTZ though....;)

 

In-fact one could make a QR 360 deg Rotator for the FTZ!

Edited by mike_halliwell
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I think I get it now let me recap.

1. The aperture control level is activated by a servo motor and not spring loaded.

2. With a CPU lens, the aperture ring if there is must be set to minimum aperture. With G lenses the aperture would close to minimum any way. When the lens is mounted the camera can read the maximum aperture and so it would know exactly where to move the aperture control level to set it at f/5.6. During the actual exposure the level would either open or close the aperture down to set aperture.

3. With a non CPU lens the aperture control level would move to minimum position and the camera would meter in stop down mode. That would make Andrew happy.

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Thanks for that informative post, Shun.

 

Do Ai lenses work the same as AF (D) ones? Do they stop down up to f/5.6 (and no more) while metering, etc. if you set the aperture to f/5.6 or higher?

 

I think Shun already said that the AI and AF lenses work differently. With AF lenses you set the aperture to minimum and select the aperture via the dial. The camera will set the aperture to f/5.6 for viewing and to set aperture during the exposure. With AI lenses you simply set the aperture on the lens and you will be viewing and metering at whatever aperture you set it for.

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I think Shun already said that the AI and AF lenses work differently. With AF lenses you set the aperture to minimum and select the aperture via the dial. The camera will set the aperture to f/5.6 for viewing and to set aperture during the exposure. With AI lenses you simply set the aperture on the lens and you will be viewing and metering at whatever aperture you set it for.

Thanks. I was confused because he referred to the Ai-S lens as a 35mm/f1.8 AF-S.

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Ah, yes the FTZ > Z body offset.

Had they made the camera a tad higher to eliminate that offset, there might have been sufficient space for a 2nd card slot. And a lot less complaints about the camera being too small.

 

So one does have to set actively set G/E lenses to maximum aperture if one wants to make sure AF has optimum conditions for accuracy when using fast glass? Not paying attention means AF will always be performed at f/5.6? Or even slower with a native Z-mount lens?

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Sorry, I fixed one typo. I don't have any 35mm/f1.8 AF-S. Both of my 35mm lenses are f1.4, one AI-S I bought back in 1987 and the other the Sigma Art. Those lenses are on the far left and far right in the 5-lens image above.

 

Somehow there is the obsession to make the mirrorless cameras small. The Z6 and Z7 are a bit larger than the Sony A7III. To me, the Z bodies are too small. And additionally I wish there were an FTZ adapter without G lens compatibility so that we can get rid of that tripod mount and motor inside, but an FTZ for E lens only will have a pretty narrow appeal.

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but an FTZ for E lens only will have a pretty narrow appeal.

It would pretty much be a tube with pass-through contacts, like a 30.5mm extension tube. (well non-Nikon 'cos they don't make AF tubes)

 

I guess it finally looks like a bigger 4 bayonet EOS mount, just 11 connection pads/pins, aligned with the lens axis, not perpendicular to it and no mechanics in sight.

Edited by mike_halliwell
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Sorry, I fixed one typo. I don't have any 35mm/f1.8 AF-S. Both of my 35mm lenses are f1.4, one AI-S I bought back in 1987 and the other the Sigma Art. Those lenses are on the far left and far right in the 5-lens image above.

 

Somehow there is the obsession to make the mirrorless cameras small. The Z6 and Z7 are a bit larger than the Sony A7III. To me, the Z bodies are too small. And additionally I wish there were an FTZ adapter without G lens compatibility so that we can get rid of that tripod mount and motor inside, but an FTZ for E lens only will have a pretty narrow appeal.

 

The price of the FTZ is only $149 when you buy the camera and if Nikon sell the E adapter only for said $100 it wouldn't be bad. One can have both adapter.

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I suspect we're a couple of years from there being enough coverage with either native Z lenses or sufficiently modern E aperture F-mount lenses (and with some expected overlap) that it makes sense to remove the aperture lever - or to put it another way, there are still too many lenses with aperture levers that are useful, and I'd still like the option to toggle between wide open and stopped down with a manual lens. Though if Nikon ever update the 14-24 to one with less field curvature, I'll be saving more urgently than my current NAS. The big superteles have long lives, and I'd need quite a financial windfall for my 200 f/2 not to be in my bag for some time. (Or I get poor enough that I need to sell it.) E aperture has always felt like it's mostly a benefit to the third parties who already needed electronic apertures for the EF mount.

 

I'm a bit astonished that the FTZ bulge has to be quite that big. Surely they could have made a ring motor or something to avoid the bump, and most small motors are pretty tiny - the aperture lever doesn't have to push that hard against the lens spring (and dropping to wide open is entirely the lens spring's problem, so even a lack of oomph would only mean the lens opened up again more slowly). Does the mechanism really take up that much space inside a camera?

 

Pretty much everyone has complained about the FTZ lump alignment. Maybe Nikon thought a larger lump would allow a QR to be attached without interfering with the camera - but that's clearly not the case. I can vaguely see a point in having a combined plate screwed into both bases for stability, but then you're stuck with F mount lenses. Making an adaptor without an aperture lever is one workaround (and if Nikon don't, I'm sure Fotodiox et al. will) - but a better solution would be to make the thing smaller. Given the extra radius of the mount, I really hope it'd be sturdy enough to hold a 14-24 or similar without needing a mounting point.

 

Out of interest, we know the adaptor works with non-electronic F-mount lenses, but does the camera itself dry fire? (As in, if you had a purely mechanical F-to-Z adaptor, could you use it?) I could believe someone might have implemented things such that the electronics in the FTZ are needed for the camera to work.

 

Anyone taking bets on whether we'll ever see a dSLR (I imagine in the D3x00 range) without an aperture lever? It's another way of cutting costs and weight (and selling more expensive lenses). So is mirrorless, although it's a fairly close-run thing if you're comparing with a DX pentamirror - the D3500 is already lighter than an Eos M5 and smaller than a Z 6.

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Out of interest, we know the adaptor works with non-electronic F-mount lenses, but does the camera itself dry fire? (As in, if you had a purely mechanical F-to-Z adaptor, could you use it?) I could believe someone might have implemented things such that the electronics in the FTZ are needed for the camera to work.

Can't say about the Z cameras, Sony's A7 Series sure do - if one enables the option in the menu. Which one has to if one wants to, for example, mount M-mount lenses via an adapter (that's nothing but an empty tube with mounts on either side).

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The price of the FTZ is only $149 when you buy the camera and if Nikon sell the E adapter only for said $100 it wouldn't be bad. One can have both adapter.

For those who purchase in the US, please keep in mind that the $100 discount on the FTZ while you purchase it with either a Z6 or Z7 body is good through the end of 2018. Starting from January 1, 2019, the price for the FTZ will jump back to $249, although Nikon can always provide that discount again.

 

I would imagine some third parties will produce their versions of the FTZ adapter for less, maybe a lot less. It looks like AI, AI-S lenses don't use the mechanical aperture control inside the FTZ either. Therefore, there could be one simple FTZ for AI/AI-S lenses and strangely, E lenses as well. (Or one really simple FTZ without any electronics for manual-focus lenses, without CPUs, only.)

 

BTW, I assume Nikon feels that we are better off using the capture aperture for composition, metering, and AF. That may help avoid focus shifting issues, i.e. focus change when we vary the aperture. That is why anything f5.6 or faster uses the selected aperture. I can understand anything slower than f5.6 is too slow for accurate AF and metering. I should also check some super teles like 300mm and above and see whether this behavior changes with teles.

 

Please keep in mind that these are my early observations. There can easily be errors due to my part of some of my lenses are not working right.

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With any AF, AF-D, and AF-S lenses on the FTZ, as well as native Z-mount lenses directly on the Z camera, during composition, when you control the aperture with the sub-command dial, the lens' aperture actually closes down from the maximum to f5.6, but when you change the setting to something smaller such as f6.3, f8, f11, the aperture on the lens would not close further down below f5.6, during composition and metering. Hence we are using partial stop-down composition and metering.

 

This is an interesting feature! It largely eliminates problems with focus shift that can occur between full-aperture focusing and the stopped-down shooting aperture. Focus shift happens mostly at wider apertures, any residual focus shift beyond f/5.6 will be minor and covered by the increased depth of field. Not stopping down beyond f/5.6 ensures enough light reaches the meter for accurate metering in low light conditions. Very neat.

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This is an interesting feature! It largely eliminates problems with focus shift that can occur between full-aperture focusing and the stopped-down shooting aperture. Focus shift happens mostly at wider apertures, any residual focus shift beyond f/5.6 will be minor and covered by the increased depth of field. Not stopping down beyond f/5.6 ensures enough light reaches the meter for accurate metering in low light conditions. Very neat.

 

For what it's worth, I think it might have been roughly the way live view got implemented in the D700 generation (I've forgotten) - there was a point past which it wouldn't stop down, IIRC. The Z series also need enough aperture for the PDoS points to work, so that's presumably quite motivating in not going slower.

 

I don't why the camera wouldn't dry fire. I think all Nikon cameras would dry fire without any lens attached.

 

I don't have evidence that they won't, I could just believe that there might be a mild simplification possible in the design if Nikon decided that "nothing connected" meant "something is wrong or at least the lens or adaptor isn't properly attached". This isn't really an option for the F mount, because there are too many manual lenses out there - but presumably nobody has ever made a completely non-electronic lens in the Z mount, so Nikon could choose to put the necessary logic to work in manual mode into the F mount adaptor - then you'd be able to tell the difference between "adaptor is loose" and "manual lens". The main side effect would be to complicate matters for people producing cheap lens adaptors, and that might not be something that Nikon management see as a disadvantage (irrespective of what customers think).

 

That said, the EF mount was always entirely electronic, and works fine with mechanical lenses - so long as you don't want luxuries like focus confirmation... Even the D3400 and D3500 do work with manual lenses, and two of my most recent lenses have no electronics (or aperture lever) - the 20mm Mitakon macro and the 58mm Petzval. (The former has a wafer thin depth of field anyway, and has to be stopped down by hand, although the choice between "extremely soft" and "triangular aperture" is somewhat making me think "I wish I'd paid twice as much for the Laowa" - though I'm not sure I use it enough to justify that. The latter has drop-in stops, and since the point of it is the weird bokeh I've always shot it wide open.) I suppose it's ironic that my other two recent acquisitions (85mm Sigma, 70-200 FL) are both E-aperture.

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This is an interesting feature! It largely eliminates problems with focus shift that can occur between full-aperture focusing and the stopped-down shooting aperture. Focus shift happens mostly at wider apertures, any residual focus shift beyond f/5.6 will be minor and covered by the increased depth of field. Not stopping down beyond f/5.6 ensures enough light reaches the meter for accurate metering in low light conditions. Very neat.

Thanks Roland. I had made essentially the same point after focus shifting in the post right before yours, but you have added more details.

 

I am wondering whether Nikon would further fine tune this behavior, e.g. the cutoff point for a 35mm/f1.4 could be different from that for a 35mm/f2.8. The behavior for a 600mm/f4 could be different from that for a 24mm/f1.4. So far my experience is that the cut off is uniformly f5.6, but as I said I need to experiment further.

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Does the FTZ have a tripod thread in the base?

If so the 'lump' makes perfect sense. Nikon's thinking is obviously that you use the FTZ as the tripod or QR plate mounting point. Since when using adapted lenses, which are generally heavier than native mirrorless ones and added to the weight of the adapter, the whole centre of gravity of the system is moved forward. Basically you're letting the beefy-looking FTZ adapter take the mounting strain, while the camera mount only has to support the weight of the camera itself.

 

Of course, this doesn't really help the ergonomics when the adapter is handheld, but I think it's an acceptable compromise. And if it really irks enough people, I'm pretty sure a spacer plate will soon be marketed by an enterprising 3rd party.

 

Having used adapted lenses via an all-metal mount adapter on a lightweight MILC body, I can entirely get where Nikon are coming from with this. I just wish my 3rd party adapter had a flat tripod foot and threaded hole!

 

I've mentioned before that lightweight MILCs need to be thought of as a lens with camera attached, and not vice-versa.

Edited by rodeo_joe|1
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I am wondering whether Nikon would further fine tune this behavior, e.g. the cutoff point for a 35mm/f1.4 could be different from that for a 35mm/f2.8. The behavior for a 600mm/f4 could be different from that for a 24mm/f1.4. So far my experience is that the cut off is uniformly f5.6, but as I said I need to experiment further.

 

Focus shift is mostly caused by spherical aberrations, where the outer part of the lens focuses light closer than the central part, so as you stop down and the outer parts of the lens are blocked by the aperture blades, the focus point moves further out. This effect is most noticeable at wide apertures, after closing down a couple of stops spherical aberrations are largely eliminated.

 

So, a different approach could be to have stop-down viewing/metering for only the first two stops or so. For an f/1.4 lens that would mean stop-down metering until f/2.8, while an f/2.8 lens would stop-down to f/5.6. There would still need to be an f/5.6 cut-off to give the meter enough light, and also so the focus plane is clearly distinguished from the fore/background so the AF system can lock onto the subject.

 

Nikon could also have information specific to each lens telling the camera how far to stop down the lens.before focus shift is no longer significant. This could be dependant on the camera resolution (high resolution is more sensitive to focus shift) and to the focus distance (focus shift may be more or less significant at different distances). I doubt this sort of information is already present in the millions of CPU lenses already made, so would require tables of lens data in each camera. This is probably not practical, and wouldn't work for third party lenses.

 

I think in the end, Nikon chose a simple and practical approach which works for all lenses pretty well. Lenses with a maximum aperture of f/5.6 or slower probably have very little focus shift - spherical aberrations mostly affects faster lenses - and slower lenses are mostly shot nearly wide open so focus shift will hardly be a problem. Another benefit of this method of viewing and metering is that you get full-time DOF preview at wider apertures, where it matters the most. Also, there is no discrepancy between the set aperture value and the actual stopped down so exposures should be more accurate.

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Is anyone hearing anything about a 3-rd party working on a replacement/alternative mount adapter?

I would definitely go for an adapter that did not have all those motors but instead featured drop-in filters (like they did it with the new Canon).

I am completely phasing out all my non-AF-S, mechanical aperture glass, so, I would rather not even have all those motors in the adapter, that come with their inherent complexity, added weight, bulk and a steep price tag. I would imagine that given the "lighter" specs, making an adapter that was flush with the body is doable. We're basically talking about a high-quality, all-metal, macro extension tube, with a bit of electronics (if any). Even with the thing for the drop-in filters, an adapter like that shouldn't be too expensive. I'd drop like 100-150 bucks in a heartbeat on those specs.

 

And whatever happened to the vertical grip for this thing? Is it even in the works?

Edited by david_r._edan
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Does the FTZ have a tripod thread in the base?

If so the 'lump' makes perfect sense.

 

My understanding is that the lump does have a tripod thread. The problem is that the thread on the camera body, which is already quite thin and needs to have room for the tilting LCD, is near the front of the body. The adaptor is also not very thick and goes right up to the camera body. The result is that, as I understand it, the adaptor tends to foul on any QR plate (at least of Arca-compatible or the various Manfrotto designs) attached to the body, and I suspect any QR plate attached to the adaptor would stop you from taking it off the camera. No problem if you don't like QR plates and just screw your camera directly onto a tripod head, or if you only ever use either the bare camera or the camera with the FTZ on it rather than switching, but annoying for the other 99% of us. Not that Nikon has a great track record when it comes to ways to attach things to a tripod.

 

My best suggestion, pending some kind of spacer, would be to see whether Arca's "monoball fix" QR plates would work, because they're thinner and taller - but as far as I'm aware nobody is cloning them (which is one reason I believe Arca tried to introduce another standard), and the only compatible head I've got is one of the dual-level clamps, which would probably still foul on the camera.

 

I suspect third parties will solve it with slightly taller than usual plates, but given that we generally want QR plates to be as wide and flat as possible for rigidity, it's an annoyance that I'd like to think shouldn't have happened.

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Is anyone hearing anything about a 3-rd party working on a replacement/alternative mount adapter?

 

MTF services announced some lens adaptors to Z, but not a replacement for the Nikon one. I've not been following beyond that. Given the grumbling, I suspect we'll see something; there are also requests for an adaptor with screwdriver focus, which might be harder.

 

And whatever happened to the vertical grip for this thing? Is it even in the works?

 

My understanding is that a very rough prototype (well, not very ergonomic, IIRC) was shown in a box at a trade show; I've not heard anything since. I don't believe there are contacts on the bottom of the camera for controls on the grip, although there might be in the battery compartment. While I'm sure real-world battery life on the Z bodies isn't as bad as some might have feared, it feels like it should allay the fears of some potential buyers to have supplemental power available. If Nikon don't do it, I'm sure someone else will. The Z 6 weighs more than 600g; while it's light for FX, I don't think Nikon should be too paranoid about adding to the size in order to round out the system - the D3500 is much lighter and a bit smaller if you're trying to cut down on those aspects of the camera, and the Z 6 with the FTZ on it weighs more than a Df.

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