Nikon Introduces Df Retro DSLR

[ShunCheung]

<p>I also have the impression that stop-down metering is not as accurate.</p>

[Andrew Garrard]

I'm not sure I understand why the aperture lever behaviour is a factor - though I can see that it would

require explicit support - but thank you, Bjorn, for leaking that much information! (When I get my head

around it, I'm sure I'll add the reason to the list of obscure Nikon knowledge that this forum has taught

me.)

 

Edit: Assuming a lens with an aperture ring (rather than the not entirely reproducible lever movement), why, Shun? Since nothing since the FA has used closed-loop metering, I'd expect stop-down to be, if anything, better. Though I could imagine the matrix might not play with an unknown aperture (I understand it might need to work out absolute EV).

[bjørn rørslett]

<p>Shun: "I also have the impression that stop-down metering is not as accurate".</p>

<p>Maximum sensitivity and lowest error for the meter is when all light comes through the lens of course. If the max. aperture is known then computing the equivalent exposure for another f-number is a breeze. However, that assumes the camera *knows* what this aperture is, which in turn requires a linkage lens-camera. Alternatively, the camera logics can assume the lens is set correctly to that specific aperture value (the Df approach for non-AI lenses). That has to be balanced against the less accurate, more error-prone reading of a lens stopped down to the actual aperture to be used. Here there need not be an actual linkage in existence.</p>

[ShunCheung]

<p>Sorry, I think our little discussion about metering here is getting academic, but the problem is that since as soon as you mount the lens, the lever on the camera will immediately open up the aperture to its maximum, stopping it down to perform stop-down metering becomes complicated. How do you stop it down? Do you want to press on depth of field preview?</p>

<p>If people insists on using unmodified pre-AI lenses, maybe Nikon should introduce a variation to the Df body: like DF, pre-AI? :-)<br>

(I am joking about a specific, pre-AI equipped version of the Df body.)</p>

[marc_ravignat]

<p>Bjorn,<br>

I have a 35/2.8 Nikkor-S non-AI (1967) presently mounted on my DF, so that would not be one of the lenses that don't work on the DF. It works like a charm. As you mentionned, on aperture priority you simply visibly choose an aperture with the ring on the lens and meter through the viewfinder with the control dial (I use the main dial) so that the aperture corresponds with the pre-set aperture on the lens. It's easy and just as fast as rotating the aperture ring while looking through the viewfinder in aperture priority with AI lenses. </p>

[bjørn rørslett]

<p>Well, my 35 is older and had issues. So did my 5.5 cm Micro-Nikkor. But certainly there aren't many Nikkors you cannot physically attach to the Df.</p>

<p>I switched over to M mode for the Df, but otherwise I do the same as you describe. Setting the aperture is always the first, crucial step. no matter what lens type I use. However, I have almost no pre-AI lenses left as 99% of my Nikkor have CPU installed in them. So I don't need to bother with the fuss of adding lens data into the camera.</p>

[simon_crofts]

<blockquote>

<p>Setting the aperture is always the first, crucial step. no matter what lens type I use.</p>

</blockquote>

<p>Are you sure you need to set data for an AIS lens? I've been using AIS lenses on D700's and D2x's, and you can use them without setting lens data no problem, including TTL flash.</p>

<p>The main disadvantage of not setting lens data is that it doesn't show aperture value on in the LCD, you can only see it on the lens itself. Not sure whether there are other advantages to setting lens data eg. whether Matrix metering will be enabled rather than just centre weighted, but basically the AIS lenses work fine without any kind of input.</p>

<p>I'd be surprised if the DF wasn't the same.</p>

 

[bms]

<blockquote>

<p>Not sure whether there are other advantages to setting lens data</p>

</blockquote>

<p>Not that this would affect IQ, but it also puts the right number for focal length and aperture into the EXIF data... </p>

[dan_south]

<blockquote>

<p>The problem is that the horribly confused interface of your typical DSLR negates this advantage and confuses the hell out of the user. What should be simple becomes complicated.</p>

</blockquote>

<p> <br>

That's why no one takes pictures anymore. Digital cameras have apparently killed off photography. <br>

<br>

Except for the amazing fact that more photographs have been taken in the last four years than in all of human history before 2010. Hmm! (Apparently it's not the interface that's confused.)</p>

[dan_south]

<blockquote>

<p>use the DSLR to take a 'test' shot, analyse the histos critically and apply those correct exposure settings to the 5 x 4 shutter.</p>

</blockquote>

<p> <br>

Not a good idea unless you can fine tune your DSLR's settings so that the JPEG preview that it creates for each frame (and upon which the histogram is based), mimics exactly the contrast curve of the film that you're shooting. That shouldn't take more than six or eight months of engineering and a few more months of custom firmware programming.<br>

<br>

Forget the histogram. Learn to use a spot meter with a particular film. Know exactly what that film will look like at 0, +1, +2, -1, -2, and -3, and you'll be able to expose most scenes with a few spot meter measurements and some quick thinking.</p>

[bjørn rørslett]

<p><em>Simon Croft: Setting the aperture is always the first, crucial step. no matter what lens type I use</em>.</p>

<p>Setting the aperture on the lens itself, of course. The action photographers have done for ages long before any computers or digital cameras existed. You may even set the aperture on the lens before the lens is mounted on the camera. </p>

<p>When the camera knows the lens data, either by using a CPU lens, or by telling it which non-CPU lens is attached, metering improves since also colour matrix metering is enabled. If you just put a non-CPU AI/AIS lens on the Df, it will meter but Nikon informs you less accurately, and of course there is no relevant EXIF data recorded. Only exposure modes A and M are available.</p>

[simon_crofts]

<blockquote>

<p>When the camera knows the lens data, either by using a CPU lens, or by telling it which non-CPU lens is attached, metering improves since also colour matrix metering is enabled.</p>

</blockquote>

<p> <br>

That's only an improvement if you like matrix metering! EXIF data - yes, that would be nice, but if I remember correctly you have to tell the camera each time you switch a lens, otherwise it thinks the previous lens was still on, and gives the wrong EXIF data, which is worse than none at all. For those of us who are often changing lenses several times a minute, that's not a good solution, so if you're happy with centre-weighted (and as far as I'm concerned, it's superior to Matrix for reasons I already mentioned), then it may be best not to set the lens data at all.</p>

[Andrew Garrard]

<p>Simon: Trust the matrix! (Never send a human to do a machine's job.)<br />

<br />

Seriously, an incorrect dialled in aperture is a problem switching between non-electronic lenses, but it's automatically overridden when there's an electronic connection anyway. The matrix can get confused, but actually it's sometimes convenient that it can get it right without too much need for thought, and without the amount of input needed for a spot meter. I'd really hate to try to guess the difference between the centre-weighted metering and the exposure value I wanted for the subject on every occasion, though I can see merits to the centre weighting behaviour being more repeatable (the matrix is less likely to be <i>predictably</i> wrong). I believe the matrix contains some smarts to try to work out the absolute brightness of the scene (so that it knows when it's looking at snow, for example), and might know something about the exit aperture and effect on vignetting, so it's helpful for it to know the lens details. I've not seen an official description of what the matrix does, though, and to the best of my knowledge it's Nikon internal secret sauce.<br />

<br />

Shun: Yes, I was assuming that "stop down metering" for a lens with an aperture lever (as opposed to my tilt-shift lenses, and an EF mount fish-eye that I used to own, which had not aperture connection to the camera at all) involved holding down DoF preview, then holding exposure lock. Older film cameras, I believe, metered whatever was going through the aperture at the time, so the meter reading would change when you stopped down; that would let you work out your settings. On a camera with automatic aperture control, things are more complex; hence I'm under the impression that stop-down metering doesn't work on any DSLR, but could be wrong. Supposedly (by KR's list - but he also claims it should work on the Df, which is really why I'm asking) the F4 and an adapted F5/F6 support stop-down metering on pre-AI lenses. I've obviously never tried it, my only non-AI lenses having no lever, but I'd be interested to know what exactly the situation is here.<br />

<br />

The Df <i>is</i> the pre-AI variant (though if they put a coupler onto the finder so that it actually engaged with the rabbit ears, I'd be impressed). I'd take a flip-up tab option on the other cameras. I suspect the same "tell the camera the aperture you're going to set" thing would be needed for the meter to work if stop-down metering doesn't, so my assertion that there wasn't any need for a firmware change may have been optimistic.<br />

<br />

I was going to ask a confused question about whether the camera actually moves the aperture lever through its whole range when the aperture is set via the aperture ring (i.e. does turning the aperture following ring affect the distance the aperture lever moves even if the lens doesn't have a hard stop), but then I realised that nonlinear apertures mean that the camera has to leave the motion to the lens. I mention this in case anyone gets as confused as me! (Though I still think it should be possible to tell the camera that an AI-S lens is attached and have automatic aperture control.)<br />

<br />

On a related note, I believe the D3 series, D4 and D800 can move the aperture lever dynamically (i.e. if you hold down DoF preview and change the aperture on the camera, the aperture changes; if you zoom a variable aperture zoom the aperture lever moves to compensate) and the D700, D600 and D610 can't (you need to release DoF preview and press it again). I believe the D800 got this as part of its video support - so you can change the aperture while shooting, though this obviously wasn't a concern on the original D3. I'm reasonably confident of the D700's failings here (I think my F5 was the same), and less so that I'm right about the D600/D610 behaviour. I'm assuming that the Df follows the D600, since it seems to have a very similar shutter mechanism (and video won't have been a priority), but could anyone confirm that? They don't tend to put it in the manual...</p>

[simon_crofts]

<blockquote>

<p>an incorrect dialled in aperture is a problem switching between non-electronic lenses</p>

</blockquote>

<p>Andrew - not if you're using AI manual focus lenses it isn't! The camera (at least D700's etc., I assume the DF hasn't gone backwards in this respect) deals with the manual non-electronic lens seamlessly and gives correct exposure without you having to tell the camera what lens is on the camera or what it's maximum aperture is. </p>

<p>From my point of view, I'm not really sure why one would want to use pre-AI lenses. AI manual lenses are so cheap secondhand, there seems to me to be little point in using pre-1977 lenses, at least on a day-to-day basis. I can understand that it's nice to be able to use them if you happen to have one in the cupboard on a particular day and don't have time to sell it and buy an AI lens, but otherwise, I don't see the point, unless perhaps there is a rare focal length etc. that's not available in AI.</p>

[Brian1664876441]

There are several Nikkor lenses that were never made in Ai, some people love them. the 5.8cm F1.4 is a favorite portrait lens among many users. The Sonnar formula 105/2.5 was never produced in Ai mount. And, as many Leica users have learned- older, single-coated and uncoated optics give a nice rendering when used on a Digital camera. My M Monochrom often has a 1936 uncoated 5cm F1.5 Sonnar or a 1950 KMZ J-3 on it.

 

You can always "slice and dice" the aperture ring to convert a non-Ai lens; I had that done on a Nikkor-UD 20/3.5. I prefer the Df approach for my Non-AI lenses. Plus the aperture wheel is about where the Focus wheel is on an Nikon RF.

[bjørn rørslett]

<p>Andrew: My D600 behaves exactly like the D800 as you described it, thus I think this relates to the manner in which the camera is set up. Moreover, pressing the preview button will disengage the meter (this is by design to prevent stop-down metering).</p>

[bjørn rørslett]

<p>Brian: the front wheel for setting apertures is the default on Df, but you can move the functionality to the rear wheel instead. If you set up the camera to use the aperture ring on the lens itself, the wheels only control apertures on a "G" lens.</p>

[Andrew Garrard]

<p>Simon: Actually, now I'm going to be really confused. The aperture following ring tells the camera what the current selected aperture is, I believe. I understand that the lip inside the mount provides information about the <i>maximum</i> aperture. Since I've always set the values for my AI lenses, I don't actually know whether the D700/D800 etc. (and, to be on topic, the Df!) have a feeler for that ring (and/or the focal length indexing ridge). If they do, maybe the number in the menu should be redundant for more lenses than I'd realised - only real pre-AI lenses or those with no coupling would need it set in a menu.<br />

<br />

Bjorn: That's good news; thank you.</p>

[simon_crofts]

<p>Andrew, I'm not well up on which coupling is used for what on the Nikkor lenses, and which may be being read. But it has certainly been the case, with the D700 and the D2x before it, and I presume the D800 and DF must surely be the same, that the camera can read the aperture on AI-type lenses to give correct exposure. It doesnt tell you the aperture in the LCD and in EXIF data, but the camera gets the exposure right, both with ambient light and TTL flash (though I haven't got to the bottom of how TTL flash exposes in this case in the corner of the frame - it doesn't seem to use centre weighted, because it gets the exposure right, not particularly over-exposed as you might expect if it was centre-weighted. But I haven't done scientific-style tests on this).<br>

In my view, there is little point in setting lens data in the camera for an AI lens, unless you're really keen on colour Matrix or on EXIF data. The inconvenience of having to change this setting, and the risk of forgetting to do so is too great. Better just to stick the lens on the camera, and take pictures, it works well. In practise, I barely notice whether I have my AI manual focus lenses on the camera or AF lenses.</p>

 

[Andrew Garrard]

<p>I think my confusion is that if the camera already knows the aperture (by knowing the maximum aperture and the aperture ring position), I'm not sure why you need to set it in the menu as well. I'll do an experiment when I'm home and near my camera... (but if anyone's in a position to prod some levers in their camera body, please tell me!)</p>

[ilkka_nissila]

<p>For me at least, storing the correct exposure details in the EXIF is useful when I'm debugging the results I need to know this information, and I'll often refer to it afterwards. I don't mind selecting the lens from the list; I don't have that many lenses without chips on them. Also using a different type of metering (centerweighted) on some lenses and another (matrix) on others would lead to confusion in what kind of correction needs to be applied. When I use automatic exposure I typically use matrix metering and compensate as needed, and when I need to obtain precisely controlled exposures I can use either the spot meter in the camera or a separate hand-held meter. I don't use the centerweighted meter; I think it is good for people who trained using it, but I've always been a spot/matrix/incident meter user and I'll stick to what I know. </p>

[simon_crofts]

<blockquote>

<p>Also using a different type of metering (centerweighted) on some lenses and another (matrix) on others would lead to confusion in what kind of correction needs to be applied.</p>

</blockquote>

<p>Consistency, as you say, is very important. It's another reason why I do like centre-weighted. If I'm switching lenses constantly - during something like a wedding I will switch lenses literally hundreds of times and be doing it fast. I don't want exposure modes to be changing. But when I'm shooting my own work I'm also typically using a Nikon and something like a Mamiya 7 simultaneously. Centre-weighted is pretty much standard across makes (though the details of the size and emphasis of the centre vary a bit) and a simple unified approach across different cameras and manufacturers reduces the potential for mistakes and allows me to remain in control of the picture-taking process.</p>

 

[Dieter Schaefer]

<blockquote>

<p>...by knowing the maximum aperture and the aperture ring position...</p>

</blockquote>

<p>Andrew, with an Ai (or Ai-S) lens, the Ai indexing ridge indicates the relative position of the aperture ring - it doesn't communicate the maximum aperture or the absolute aperture (though the start position of the indexing ring naturally contains the information on the maximum aperture - this would suffice if the lens was mounted always with the aperture ring set to maximum aperture). The maximum aperture is given to the camera by the "maximum aperture indexing post of a Ai or Ai-S lens. Many Ai'd lenses lack that indexing post - they only had the indexing ridge added - I don't know whether the original Nikon modification included the addition of that indexing post or not. It's most important feature was to allow AMP with the FA and F4 (more here: http://www.zi.ku.dk/personal/lhhansen/photo/FullAImod.htm)<br /> Pre-Ai, the maximum aperture (entire range actually) was communicated to the camera; not so with Ai; it's a relative indexing mechanism.</p>

<p>It is, however, a good question, why one has to manually add the aperture of an Ai/Ai-S lens in the menu because the camera should already know.</p>

[ShunCheung]

<p>What AI and AI-S cannot communicate mechanically to the camera body is the focal length.</p>

[bebu_lamar]

<p>The AI and AI-S lenses do not communicate the maximum aperture to the camera at all. The pre AI lens in fact does for the cameras that support it but requiring the manual indexing mounting ritual. However the cameras of that period only use the information to display the aperture in viewfinder. The aperture scale in viewfinder is built in to the camera. Most cameras of the AI/AI-S lens period use the aperture direct readout to reflect the aperture number from the lens to the viewfinder. </p>