Nikon Introduces Mirrorless Z System

Discussion in 'Nikon' started by ShunCheung, Aug 23, 2018.

  1. Yargh. The "setting the aperture in two places" solution is my least favourite botch on the Df. The Df, which has a shutter mechanism very similar to the D610, can't move the mirror independently of the stop-down lever, so doing stop-down metering with the viewfinder meter would be a bit of a hack (the aperture would open and close repeatedly, I believe). The D8x0 and single-digit bodies can move the aperture lever independently, so I see no reason they shouldn't always have been able to do stop-down metering, other than that it wouldn't work in matrix mode. I doubt improving flexibility with AI lenses is high on Nikon's priority list, but still. On the Z, the behaviour depends on how the aperture lever in the adaptor is implemented - I agree they could do it (although again, not knowing the absolute EV breaks the matrix algorithms).
  2. Agreed. I'd love it if this stuff was considered old enough to be discussed in the 1001 nights articles.

    Good thought about the viewfinder meter blacking out. The F5 could meter its centre AF point (which is how it metered with a WLF); I'm not sure how the FA managed incremental stop down. Did it not have a fresnel finder screen?

    I'm sure we'd lose the matrix metering doing this, because the algorithm (AFAIK) needs to know absolute light levels for its scene detection. That doesn't mean we shouldn't be able to spot meter. Or even highlight meter, as far as I'm concerned.
  3. It is fairly simple to use a manual aperture ring on an MILC. Exposure is measured by the image sensor, and always in the stopped-down position. Set the manual coupling in the adapter to the widest open position, and the aperture will always close to the value displayed on the ring. The camera doesn't need to know (unlike a DSLR) what the maximum aperture is, nor where the ring is set.

    The aperture setting may or may not be displayed in the finder or in metadata. It's possible if the Z can read the chip in the lens, if any. Alternately, the Z probably has an ambient light sensor to adjust the finder brightness. Leica uses this reading to compare with the light reaching the sensor in order to estimate the f/stop.

    If you use the slider on the adapter to set the aperture, first set the manual ring to the smallest aperture and the lever will open the lens to a non-calibrated value. Since exposure is always measured with the aperture at the set value, it is not necessary to know the exact value. A DSLR has a fixed set of positions for the coupling lever, and measures exposure with the lens wide open. The camera must know the maximum aperture to implement the preset value in f/stops with the number of "clicks" to move the lever at the time of exposure.

    Using an MILC, especially with focus magnification, you quickly realize DOF is a convenient fiction. On the other hand, you always have live view and the finder stays at a constant level. Since you alway view at the preset aperture, you have a very clear idea of the effective DOF. DOF control becomes a creative tool, not just a rough guess.
  4. Sorry, but AF can't "add people" to a group photo. It focuses on the subject you are pointing at, and forgets where it was last. With an EVF, you are always in "live view" and can reasonably see who's in focus. It's still necessary to use the skill you develop with experience as to where to focus and where to set the aperture.

    Most people use a half-press of the shutter release to trigger AF. If you use single-servo focusing, you can focus and recompose just like with a rangefinder camera. In order to use face detection, you must be in continuous-servo mode. If the camera detects several faces, you may be able to select a particular one using the joy stick. I use the dedicated AF button (Sony A7) and disable the half-press option. That way I can focus and recompose once, release the AF button, and shoot several frames without the need to repeat the process. That's especially useful when shooting groups at a wedding or event.

    I have even used tracking to lock on to a particular face, and have it hold when I recompose the photo. It's not something I would recommend on a continual basis.

    There are many more options for focusing and exposure with an MILC compared to a DSLR, that you will find it confusing at first.
  5. Why? The lens is not necessarily always stopped down during image preview - doing so compromises PDoS autofocus accuracy. And there's still a mechanical shutter. I'd be surprised if the sequence is "stop down, meter, close shutter, open shutter, close shutter, release aperture lever and open the shutter again". And you wouldn't be able to see metering information during composition.

    While you can stop down before metering, and indeed while composing (which gives you DoF preview), you probably also limit yourself to contrast-detect AF doing so. I don't think they're so different.

    I'm actually interested to know that. IIRC the addition and removal of an ambient sensor for the rear LCD happened during the D8x0 series lifetime.

    Well, yes. But the only reason modern Nikon bodies care is to give absolute light information to the matrix algorithm. Spot or centre-weight and the camera doesn't need to know what the absolute aperture is. The on-camera dials could implement "delta -4 EV" just as easily.

    As in live view. And as if you look at images once they're captured. I essentially don't rely on the OVF for focus confirmation unless I'm stopping down a lot.

    As in live view. Or, beyond a certain point, with DoF preview in the finder. And this does assume you're using the MILC with the lens stopped down, which inherently affects automated AF speed and accuracy and limits the light reaching the sensor. Sometimes that's a good trade-off; sometimes it's not.
  6. The Df can stop the lens down without having the mirror up. The DOF button does that. It's all about the matrix algorithm but they can change it. Personally I don't care much for metering so it doesn't bother me. If you have to stop the lens down first to take the meter reading then take the shot it's OK by me but I wouldn't do it. It's much simpler for me to simply guess the exposure. If the camera would automatically stop the lens down after you push the shutter release, take a reading and set the shutter speed automatically that would be convenient to some but I wouldn't want that because it can't display the shutter speed before I press the shutter release.
  7. We're discussing a feature addition, not disputing the current behaviour. Hold AF-On on a subject in the finder and move the camera around with 3D tracking, and the AF point will move with them. I'm suggesting that, while doing this, you could move another AF point over a separate subject, either by moving the camera or using the AF joystick. You'd have to select something which was out of focus and rely on the tracking staying locked (which is mostly up to the meter colour input), and if AF is to track you couldn't just stop down as you go to keep all the subjects in focus, but to some extent it should be possible.

    How? You're looking at a screen with limited resolution, from a limited viewpoint. The situation is not significantly better than an optical finder. You can do better if you zoom in on a focus point, but then you're not composing the scene. (See my historical suggestions for splitting the live view screen four ways...)

    Sure. But nonetheless, Canon implemented A-Dep for doing this, and (other than that they gave no control over CoC size) it was useful. I don't see why it now shouldn't be.

    In general, maybe. On this forum I suspect there are an awful lot of AF-On users. I'm not somehow suggesting this as a replacement for normal AF usage, just an alternative mode, which is exactly how Canon implemented it.

    Which on a modern high-megapixel camera, I maintain, is a terrible idea - because you tilt the focal plane as you recompose. Hasselblad actually use the accelerometer in the camera to detect rotation and refocus when you do this. Tracking is better still, because everyone (subject and photographer) moves a bit.

    At a sufficiently small aperture, I'm sure that works fine. Weren't you mentioning depth of field being a fiction? :)

    Why? It's how I normally shoot a portrait, and Nikon's eye track AF is designed for it. People don't hold still.

    I'm sure (despite my already owning two MILC bodies). But some also work just fine with a dSLR, no? Interestingly, one of the criticisms people have made about the Z series is that the configurability of Nikon's AF system seems to have gone missing.
  8. Just to keep the thread churning, rumours indicate that Canon might be announcing a 28MP, 10fps, ~$2000 full-frame mirrorless system on September 5th. Of course, rumours could say anything, but we might want to be ready for further discussion about the comparative merits of the Z6. Just keeping people awake for the weekend. :)

    (Also apologies to Ed if I was a bit cantankerous in the last post. A long day filing expense claims puts me in a bad mood, and I may have let it rub off.)
  9. Andrew Garrard likes this.
  10. And to follow on from Andrew's 'Rumour' about the Canon MILC, they appear to fave a filter housing adaptor too.
    Andrew Garrard likes this.
  11. Do you know if it has new mount?
  12. In lieu of a mechanical coupling with the camera, you are obliged to focus and meter non-electronic apertures in a stopped-down position. Buried in comments by early users of the Nikon Z, native lenses stop down once focusing is complete, which sounds very similar to the way Sony works. One source said the Z only stops down to f/5.6 prior to the shot, presumably to maintain phase detection. Sony has options in this regard, and I suspect Nikon does too, and they may change as the firmware is updated.
    Andrew Garrard likes this.
  13. True. Although the Z adaptor has a aperture lever, so it should be able to toggle between "wide open" and "anything up to minimum aperture, stopped by the aperture ring" on most Nikon lenses, as with other Nikons (and the only functionality pre-FA). I have a few lenses with no coupling; most have a quick manual way to toggle between stopped down and wide. Am I right in remembering that the trick with pre-AI lenses on bodies like the F5 is to use AE lock while holding down Pv?

    Good catch about the implementation details chosen by Nikon - similar, I believe, to live view on the D700, which would stop down but not all the way.
  14. I know nothing, but I believe the rumour was suggesting one. I guess we'll know soon!
  15. Sorry, I should be clear. I don't fully understand the aperture control mechanism, but it appears that most Nikons have a set position for the aperture lever, and stop down to it when you press DoF preview or raise the mirror (for a single shot or live view). If you change the aperture manually on the camera while holding down Pv or in live view, nothing happens until you return to normal shooting; similarly aperture is fixed for video. If you zoom a variable aperture lens, the actual aperture is determined by the lever position, not the set aperture.

    On the D8x0 bodies and single digit cameras after the D3 (and I always forget which category the D750 and D500 fall in), the aperture lever position adjusts independently. You can see aperture changes dynamically in DoF preview, you have "power aperture" in video, variable aperture lenses maintain the set aperture. Hence these bodies should be mechanically able to adjust the aperture after stopping down to meter (but not matrix meter) with a lens with a nonlinear aperture motion, I think.

    I've also forgotten whether E-aperture lenses work properly on everything (since they're not reliant on the aperture lever implementation).

    I find myself in a constant fight with Nikon's metering algorithm, mostly because even highlight metering doesn't actually preserve highlights. (Nikon: seriously, how hard would ETTR be?) But the things I shoot change enough that I rarely expose manually.

    Take a reading? The worst I was proposing was the stop down meter by Pv + AE-Lock as on the film bodies, not read the meter manually. On bodies with a flexible aperture lever (mostly including the Z adaptor) I was just assuming a slight exposure delay as on the FA, since the mirror can't be moving while the lens stops down. Aperture priority or manual with auto ISO should be able to do this stopping down to the lens aperture ring value (even on pre-AI or bodies with no aperture ring); camera aperture control (program and shutter priority) needs the closed loop system with the bodies that have the right lever control. The camera doesn't know the set aperture, but doesn't need to.

    Well, you don't have to use it, but I'm quite fond of having a meter.

    Well, there's always manual with auto ISO. But you'd really rather know the shutter speed than have the exposure metered? (Or, I guess, have metering but have to make aperture changes twice?) Even if pressing Pv could give you a shutter speed reading? Tracking the exposure difference compared with wide open so that matrix metering works would be interesting, though.

    Still, shoulda woulda coulda. If Nikon didn't care about providing at least F5-grade stop down metering with the Df, I doubt they're going to fix it on any new body. I don't actually own any pre-AI lenses, I'm just a bit sad that they wouldn't fully work.
  16. It would be interesting to know. Among all the DSLR lens mount the Canon would benefit from a shorter flange distance but not much else as it already has good communication between lens and body.
  17. Andrew!
    If you are talking about the G lenses which the X series with the FTZ adapter can meter just fine in all modes then there is no need for stop down metering.
    Lens with CPU like AF or AF-D lenses would also work without having to resort to stop down method.
    Now with AI, AI-s and Pre AI lenses the aperture is set with the aperture ring and in this case the stop down level always move to minimum aperture position whether during exposure or when the DOF button is press. The aperture can now be controlled with the aperture ring. I guess because you always use the dial on the camera even with lenses that have the aperture ring so you didn't know this.
  18. Oh yes I don't need the camera to tell me which settings I should set it at (the meter) but I want it to do what I tell it to like which aperture and shutter speed. If I let it goes auto it must tell me what it's going to do before I release the shutter. I know that Les on the forum loves his Pentax LX because it measure exposure during the the actual exposure and the shutter speed that it displays isn't going to be the actual. He loves it but I hate it. I rather have it does what it says it does regardless whether that is right or wrong because I am the one that decide that.
  19. I'm just talking about purely manual lenses - as you say, anything with electronics tells the camera about its maximum aperture that way, so aperture control can be open loop.

    I have AI lenses, and you have to use the aperture ring to control the aperture with those (on dSLRs - not the FA). My concerns are:
    • This means no camera control over aperture for shutter priority or program mode, and no accurate sub-stop aperture control. If AI-S were actually linear, you would be able to set the aperture from the camera like an electronic lens (if you told the camera its maximum aperture). I'm thinking of shutter and program being closed loop (adjust the lever until the meter is as desired), which limits it to a few high-end bodies.
    • With pre-AI lenses there's no connection between the aperture ring and the camera's following ring, so the camera doesn't know what the aperture is set to (or how much it differs from wide open) even with the aperture set by the aperture ring. The stop-down metering option on film bodies, or an automated FA-like two-stage aperture/mirror change, should allow a reading at the final exposure for automatic exposure adjustment even in this case. I don't think the Df's aperture system could automate it, but the Pv/AE-lock trick ought to have been possible. Getting matrix metering this way would require an estimated stop difference between open and stopped down (I guess based on the centre point), which could get thrown by a moving subject.
    I've now forgotten how we got onto this. But depending on the flexibility of the aperture lever in the Z mount adaptor, I guess a firmware update could handle this even if composing and setting focus at a wide aperture. (I don't believe this will work by default, but could be wrong.)
  20. If a body has IBIS, can it technically do pixel shift imaging to increase resolution/decrease noise?

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