Customizing the Df

<blockquote>Just realized two hurdles on the OCR/ADR path</blockquote>

 

<p>Good point (I keep thinking of AI vs AI-s...), although I guess you could put the reader farther forward so it was in front of the rabbit ears. You'd really want a flip-up option, though, or I'm sure it would foul on something (probably of the tilt-shift persuasion). Hmm. I wonder whether someone could build a reader that sits in the hotshoe? (Silly question, is the hotshoe in the same location compared with the sensor plane on all Nikons? Not height, obviously, just front to back. I'm excluding the F3 thing with the hotshoe off to one side, just wondering whether this is a valid accessory approach.)</p>

 

<blockquote>Set lens to wide open to focus, then set to working aperture for metering.</blockquote>

 

<p>Yes. Some lenses designed for the F mount have a half-way solution to this, such that you can set an aperture and have a way to toggle between that and wide open manually. My Peleng 8mm did this on Canon, and so do my Kiev and Hartblei tilt-shifts.</p>

 

<blockquote><blockquote>Actually, I guess it might be an issue with driving the mirror and aperture lever separately</blockquote>

 

Not sure I can follow - on the film cameras, depressing the DOF preview stopped the lens down and the meter could read at working aperture - the mirror wasn't doing anything in that scenario.</blockquote>

 

<p>You know that feeling of realising you're talking gibberish on the internet? I allowed myself to be distracted by the aperture location setting being dynamic on some bodies and one-shot on others (the most obvious difference being if you try to change aperture on the camera while holding down DoF preview - or use a variable aperture zoom). Of course, this shouldn't actually affect a lens with the aperture set using the aperture ring, because the lever should be in the fully-relaxed position anyway. I should really get the hang of how exactly the DSLRs use their motors to drive the aperture lever.<br />

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Anyway. As you say, DoF preview works. I think, and I now want to try it, metering still works in DoF preview with the aperture stopped down a bit. (It certainly does in live view, obviously, but that's not using the normal meter.) The matrix meter does rely - I think - on knowing in absolute terms how bright things are, which I believe is why you need to tell the camera the maximum aperture of a manual lens before the matrix will work (and therefore why the F5 can't matrix with pre-AI lenses but the F6 can). So I wouldn't really expect the matrix to work with stop-down metering, but I don't see why the dumb modes shouldn't work.<br />

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The tricky bit would be driving the aperture lever from the camera end (like the FA) in open-loop mode; I'm prepared to believe that you'd need the independent aperture lever motor for that, and it might be a little slow, but I don't see why it wouldn't work. Or you could emulate the DS-12 electronic aperture system, which I guess would allow you to set the aperture without requiring that the aperture lever itself be linear (I can't imagine why else you'd want to use that mechanism) - but I believe that's AI-only anyway.</p>

<p>RJ: At this point I'm not further dissing the Df - it is what it is. I just think it would have been interesting for Nikon to make a "compatible with everything" camera, since they never have, and the Df seemed to be a stab at it. I completely agree that AI is better than pre-AI (and my views on what control systems are better when are pretty public), it just seems a shame to make someone take a grinder to any remaining lenses that are, at this point, almost antique and certainly collectable. I believe a universal mount <i>could</i> be done, so it's sad that it hasn't.<br />

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Coming from the Canon EF system before I moved to Nikon, the F mount's mechanical aperture post always seemed extremely fragile and imprecise, especially when passed through a teleconverter. Canon extension tubes are mechanically trivial compared with Nikon ones, and the same is true of the Canon tilt-shift - and not having to route the aperture lever half way down the lens can only help the design of big telephoto lenses, too. So I say, all hail the new E lens designation, now Nikon has caught up. Even if it confuses me with my 50mm E (Nikon, non-Nikkor) and if it means that my F5 officially can't handle the new shiny. At some point I'll expect bodies to give up on mechanical aperture couplings as they gave up on focus screw motors (I'm still waiting for a D610 successor to be a full-frame without that), which will save us some more weight and money. And coincidentally make things a little easier for mirrorless, so long as you have an electronic attachment.</p>

<p>Actually the Pre AI coupling is capable to send max and min aperture of the lens to the camera that is why it needs the ritual to synchronize the built in aperture scale to that of the lens aperture ring. AI got away with that using ADR. </p>

<p>Calculating EVs, and mastering Sunny f16 is quite admirable, yet I can't help think that of all the modern conveniences for camera's and us, so critical of what is, or is inconvenient, of all things its a good meter that keeps me in the game. There are so many variables within the differences of ambient light and reflected light along with the varying tones of subject surfaces within feet of each other. Love the meter! Certainly there are cases when a meter reading interprets to sunny f16 dead on, but its the fringes that can make a shot. I think Nikon did a lot better with the Df than taking a stab at it, but if I'm wrong we're in for a amazing future in Photography. Did Nikon have Pre-AI lenses in mind as a priority? Probably not, as there are more AI and AI-S lenses stuffed in closets that are worthy of resurrection. The Philosophical methodology and proven public reception of the Df to date, has certainly put to rest the cynicism originally touted by its critics upon the release of the Df. As it turns out, the Df is a shining star for Nikon.</p>

<p>Regarding pre-AI support, Can the Df do stop down metering? If so, then who cares if it can read the position of the aperture ring?<br>

Also, just like a car can be properly retro without having the ability to be hitched to horses, so a digital camera can be retro without reaching so far back into the mist of antiquity as to meter normally with pre-AI lens.<br>

Okay, I'll sidle off now.</p>

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<p>Chuck: No, no Nikon DSLR supports stop-down metering. Hence my query. I mention it only in the context of the Df because the Df has partial support for pre-AI lenses - but it does so by requiring the user to set the aperture both on the lens (using the aperture ring) and on the camera. (Actually, to be fair, I'm guessing that you don't need to set anything on the camera if you're in purely manual mode and not metering in any way, which isn't so unusual for older cameras.) Stop down metering would, I believe, have been less unwieldy.</p>

<p>Don: I was a critic when the Df was launched because I was trying to understand how (or at least, when) the Df's control system might be superior to that of a more "modern" camera. I think I now do understand, although I maintain that the conventional Nikon dial system is superior under some other circumstances, and that I expect most users would agree with me in preferring it as a compromise. But I won't deny that there are those who could justifiably prefer the Df, I just think that it might have been possible to achieve its aims without some of the idiosyncrasies. I've no idea how well it's sold. However, it's not clear to me that the Df would make a difference in resurrecting AI lenses, since they work perfectly on any body from the D7000 up - it's only the Df's pre-AI support that's new. But I'm glad you (and, I hope, Christian) seem to be happy with the Df, and I completely agree on the merits of modern metering.</p>

<p>BeBu: I know the Nikon shuffle involved moving the aperture ears to maximum and minimum aperture; did this actually tell the camera what the maximum aperture was, or just the difference between the two? The AI aperture ring only tells the camera how many stops from wide open the ring is set to (via the aperture coupling ring, not the ADR hole-in-the-finder); it's only AI-S that added the absolute maximum aperture tab beside the rear element, I believe. Of course, on a digital camera you can tell the camera what the maximum aperture is manually. The difference should only matter for matrix metering (and some open-loop flash control).</p>

<p>Andrew, Yes, I think upon the initial release of the Df, there was a lot of trying to understand the function, purpose, point, value, worthiness, prowess, of the Df by all. I don't think the Df was ever intended to give the D-800 a run, or other proven Professional Nikons to replace them. In designing the Df it seems Nikon wanted to present more than one flavor in their DSLR line. It's good business. Sorry I guess this is off topic, but isn't it great that the Df is so Customizable? Also, lets not forget the Nikon mystery guest campaign prior to the release of the Df. This created a lot of anticipation by all of us, some more than others and perhaps artificially raised a bar too high. I hope Nikon has figured, although the Drum roll campaign for the Df worked in its case, that we're over it, another one of those will be sorely received. I think we are beyond this.</p>

<p>Andrew: The pre AI manual indexing system does tell the camera both the max and min aperture so that the camera can display the f stop correctly. The f stop scale on pre AI camera was built into the camera. However, AI makes sense as all this trouble only to display the aperture in the viewfinder. However, if today Nikon would use the same type of coupling and makes users do the shuffle then the users won't have to input lens data nor set aperture in 2 different places and still have full matrix metering. But my respond to Christian that in today electronic/digital age such a mechanical device would be considered expensive so I propose the OCR thingy. </p>

<p>Actually for me the Df was so easy to understand. It's easy for me to see why Nikon made it and made it that way. Why it has the features that it does and why it doesn't have the features that it doesn't all very simple to me. </p>

<p>This interesting forum string has had a lot to say - I have since dug deeper in the Df. With a Non-CPU lens (Non-AI and AI), I am still looking for a way to test preset shutter speeds for night sky exposures on a tripod. WIth B and T settings, you can't walk away without further manipulation unless T runs into its maximum time 0f 30 minutes. Without rotational guidance, I have read that a good rule of thumb to stabilize stars is 500/FL seconds. </p>

<p>BeBu: Good to know about the min/max thing. I wasn't sure if the positions for the meter were absolute or relative - I believe you if you say they're absolute. So an "ear reader" (listener?) would actually be less painful than manually setting the aperture in the camera even on an AI lens (or AI-s, since nothing digital reads the maximum aperture post), as you say. I'm not sure how much it would actually cost to add such a thing; with electronics, I doubt it would be nearly as hard to engineer as it was back in the day of the Photomic prisms. OCR would be neat, but probably not as reliable.<br />

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Don: I was defensive in some threads where people claimed that the Df interface was a vast improvement and that Nikon should move to it for all cameras; I'm much happier to accept it as an alternative for those who want it. It's still not how I would have tried to design something for what I believe is the same goal, but I guess it's better to have on the market than not. I'm glad the trade-offs are so obvious to BeBu; I remain a bit confused why Nikon launched a camera that cost the same as the D800 (at least at launch) yet had the D600's shutter, AF system and meter. I do get that not many people will care hugely about something for reading bunny ears, but that doesn't stop me wishing there was a camera that could do it (even if it wasn't the Df) - just as I don't really want a Bugatti Veyron, but I'm happy that it exists. Still, the Df is what it is, and if people are happy with it, that's all we can ask. (I'm just surprised that people with one are as happy as they are, and think that Nikon could have made more people more happy with some tweaks! But that is for several other threads.)<br />

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Christian is quite right to point out the AF bounds are a bit anomalous for the Df (which, of any Nikon DSLR, is probably most likely to be used in manual focus), though - and they're more intrusive than they might have been with a multicam 3500, because they're nearer the centre of the frame.<br />

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Christian: I was going to suggest an MC-36 remote shutter cord, which has a configurable timer, but I've just registered that the Df has no ten-pin connector to use it with. I'd hope some third party might make an MC-DC2 compatible with more functionality. Failing that, wire something up to an arduino? That said, if you're not on a tracking mount, you'll be going some to need much over 30 seconds. I've run a little longer than that (by looking at my watch), but only a couple of minutes, and that was with a fish-eye. Modern cameras, and especially the Df, are good enough at higher ISOs that you can take relatively short exposures and stack them - which is a good idea anyway, otherwise you tend to get half an hour lost when someone kicked the tripod or decided to point something out with a laser pointer. Where the skies are near me, I tend to get frames saturated with orange fairly quickly anyway, so stacking is the way to go. Good luck!</p>

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<p>since nothing digital reads the maximum aperture post</p>

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<p>Sorry for going off on a tangent - but what did that "lens speed post" add that wasn't already available with the Ai follower tab (after all, Ai is just short for "automatic maximum aperture indexing"<a href="https://support.nikonusa.com/app/answers/detail/a_id/5366/~/what-is-the-difference-between-an-ai-lens,-an-ai-s-lens,-and-non-ai-lens%3F"> https://support.nikonusa.com/app/answers/detail/a_id/5366/~/what-is-the-difference-between-an-ai-lens,-an-ai-s-lens,-and-non-ai-lens%3F</a>)? The follower tab gives the maximum aperture to the camera - and also the aperture selected. AFAIK, that's what the lens speed post does too - so why is it even there? It's also not only on AiS lenses - it's already on Ai lenses (but my F3 has nothing in the mirror box that engages it). Interestingly enough, Ai'd lenses (even by Nikon) did not have the lens speed post added.</p>

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<p>Good to know about the min/max thing.</p>

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<p>Believe it was just to communicate the maximum aperture. The "shuffle" was already an advanced version also known as "semi-automatic indexing" (which, for example, the FT did not have:<a href="http://nikon.com/about/feelnikon/recollections/r28_e/index.htm"> http://nikon.com/about/feelnikon/recollections/r28_e/index.htm</a></p>

<p>I was about to reply to Dieter, then thought there was a sporting chance of being publicly wrong twice in one thread and thought I'd come home to my camera to check. So now I have...</p>

<p>Firstly, good links, especially the second one. Thanks for those.</p>

<p>The AI meter coupling ridge <em>does</em> appear in different places on the lens according to the aperture, but because it moves with the aperture ring, the camera can't actually tell what the absolute aperture of the camera is by using it. (Unlike the bunny ears, which I should have realised always indicate f/5.6.) All the camera can do with the meter coupling lever is tell how far the aperture has moved relative to the lens's definition of "wide open". If you turn an AI lens it its maximum aperture and then mount it on the camera, the meter coupling lever (which gets pushed anticlockwise - facing the front of the camera - as the lens mounts) barely moves, no matter what the maximum aperture of the lens is. At least, according to my 135 f/2.8 (which I've been calling AI-S for a while, but turns out to be AI, and my 300mm f/4 - I'm wondering where I put my 50mm AF-D now...) For simple metering, this is all you need - you just need the difference between what the aperture is during metering (wide open) and in its stopped-down position. It's only with a matrix meter, like the FA, that you actually gain anything by knowing what the absolute aperture was - which is why it has a reader for this tab. AF lenses communicate the same thing electronically, of course, and DSLRs (and the F6) need to be told the maximum aperture for mechanical lenses because they don't sense the maximum aperture tab and rely on electronics.</p>

<p>But you're quite right, I was mis-reading the internet (again) and the maximum aperture tab is there on AI lenses too. I was confused because the lens I own that I thought was AI-S was in fact AI. I was pleased to find it's still there on my 50mm Sigma Art, even though G lenses are barely useful on the only cameras that can pay attention to it. I thought I'd seen a service that adds maximum aperture posts, but I might have imagined it. It would be much more of a pain to attach than just milling the back of the lens, though. I'm less surprised that this functionality was in AI now I understand that the bunny ear approach could do it.</p>