Using the Df with older lenses
One of the major selling points of the Df is the potential for shooting with Nikon's older, manual focus lenses. The ability to mount manual focus 'AI' lenses has long been a feature of Nikon's high-end DSLR bodies, but the Df goes one step further and allows Pre-AI lenses to be attached, too. This means you can mount almost all of Nikon's F mount lenses on the Df, with the main exceptions being the IX-Nikkor lenses designed for APS film and the two lenses designed for Nikon's first autofocus camera, the F3AF.
The amount of work required to use older lenses is dictated by their type. This is usually a function of when that design was introduced - Nikon has regularly continued to build older lens types after introducing newer systems. Here's how they all work.
Autofocus and 'CPU' lenses
As you might expect, it's generally the most modern lenses that offer most functions. The latest 'G' lenses do not have aperture rings and can only be controlled from the camera body. The older AF-Nikkor lenses (plus Zeiss ZF.2 and the three AI-P Nikkors) all feature CPUs that communicate their focal length and maximum aperture to the camera. These can be operated using either the camera's command dial, or the aperture ring if you've chosen that from the Custom Function menu (Menus/Custom/f/f7 Customize Control Dials/Aperture Setting/Aperture Ring). If you choose to use the command dial, the aperture ring must be locked at its minimum setting, so that the lens isn't stuck in a position that conflicts with the one being specified by the camera.
In general, the decision of whether to use the aperture ring or command dial is likely to come down to what mixture of lenses you're using - if most of your lenses are AF and G-type, then you'll get a more consistent experience by using the camera's dials. However, if you're using the Df to resurrect your older lenses, you may prefer to stick to using their aperture rings.
AI and Pre-AI lenses
The complications begin when you mount a lens without a CPU onto the camera. Those introduced after 1977 feature what's called an 'aperture indexing' ridge (giving rise to the AI name) that communicates the current aperture relative to the maximum aperture of the lens. Since the maximum aperture isn't specified, this needs to be manually entered into the camera. The Df allows you to define and store 9 such sets of information, via the 'Non-CPU lens data' option in the Setup Menu*.
Since the camera can't control the aperture with AI and Pre-AI lenses, you are limited to Aperture Priority and Manual exposure mode when using these lenses. With AI lenses, the camera will show the correct aperture in the viewfinder and in the EXIF data of any images you shoot. Finally, with Pre-AI lenses, the camera has no information at all about the lens' settings (beyond what you've manually entered), so you have to manually match the aperture on the lens to the one that you've told the camera using the command dial.
When using AI and Pre-AI lenses, we found it useful to assign one of the buttons on the front of the camera to select which lens we were using - you can't define a new lens this way, but you can easily switch between the lenses you've already set.
*Any data manually entered or derived from it is reported with an asterisk when played back in the camera.
|Manually enter data?||Yes||Yes||No||No|
|Aperture control||Aperture Ring||Aperture Ring||Optional†||Command Dial|
†When using AF-Nikkors ('CPU' lenses), you have the choice of using the lens aperture ring or the camera's command dial. The lens needs to be locked to its smallest aperture to use the command dial.
Manual focus with the Df
There are three major means of manual focusing with the Df - by eye through the optical viewfinder, with assistance from the camera's focus indicator, or by using magnified live view on the back of the camera. Having experimented with all three, it's not surprising which yields the best results.
The Df specifications say it uses the same Clear Matte Mark VIII focusing screen that Nikon uses in most of its full frame models. Anyone used to a pre-AF SLR will be disappointed at the lack of a split-prism focus screen (the given reasoning has always been that the differing transparency as the camera is focused can interfere with the light hitting the metering sensor which is built into the viewfinder). The screen includes an LCD layer, so it isn't replaceable - meaning there's no easy way of fitting a third-party split prism screen either.
|Focused 'by eye' (with rangefinder light lit)||Focused with Live view|
|100% crop||100% crop|
Our experience with focusing using just the screen hasn't been great but when used in conjunction with the focus confirmation rangefinder (essentially the AF sensor confirming focus) it's pretty effective. We've read the talk about the focusing screen being better than the ones used in other Nikon cameras, but we just aren't seeing an appreciable difference. In situations where depth of field is extremely shallow - for example close distances and large apertures - the focus confirmation dot will stay lit even when the lens is visibly out of focus, meaning that it's only helpful as a guide, rather than specific confirmation.
Unsurprisingly, this leaves magnified live view as the most accurate and precise means of achieving perfect focus. The camera's highest magnification is around 200%, allowing a very detailed view of the subject you're trying to focus on. It's slower than focusing using the viewfinder (since you can't assess focus and composition at the same time), but it's more consistent in giving the correct result.
Shooting experience with older lenses.
The appeal of using older lenses on the Df is not just practical, but also aesthetic. The 'aesthetic' element here is that all of Nikon's manual focus lenses, AI and Pre-AI, are a beautiful match for the Df's self-consciously 'traditional' design.
So what's it like to shoot with older lenses on the Df? Well, it's a mixed bag. I'm used to using Ai manual focus lenses on Nikon DSLRs, and the experience of programming-in the basic lens data, mounting and shooting with an old manual prime on the Df is identical to any other recent high-end models. On the 36MP Nikon D800 I have had serious issues achieving correct manual focus on fast primes using the focus indicator, but the more modest pixel count of the Df means that the sort of minor focusing inconsistencies that can be irksome on the D800 aren't quite as noticeable. Setting the aperture manually using an aperture ring on the lens is easy, fun and feels very natural (especially if you grew up with it).
As with many recent high-end Nikon DSLRs, you can opt to use the lenses' aperture rings if you like, instead of the camera's command dials, by activating a well-hidden custom function. Normally I wouldn't bother with this (since with the manual aperture ring you're generally limited to aperture control in whole stops, and you can't shoot in shutter speed priority or program modes) but the Df cries out to be used as manually as possible, so I dutifully engaged the custom option and loaded my bag up with primes. As expected, the experience is just as fluid as it is on a 'classic' manual focus lens. Some of my AF-D optics have fairly stiff 'dry'-feeling aperture rings which aren't as nice to use as the older lenses but I'd put this partly down to lack of use.
|The Df has allowed me to re-use lenses such as my Micro-Nikkor 55mm 1:3.5 I never expected to be able to use on a digital body.|
It's a similar story with older, pre-Ai lenses: you just go into the menu and program in the vital statistics - focal length and minimum aperture, making sure to distinguish it as 'non-Ai' - pop the little meter coupling tab on the lens throat out of the way, and attach the lens. The difference is that the camera doesn't know the position of the aperture ring - you have to tell it. Treating the camera like an external light meter you adjust aperture using the camera's command dials, establish the desired exposure settings, then transfer that aperture to the lens's physical aperture ring, and fire away. It takes a little getting used to, but it's perfectly practical and actually a lot of fun.
In my experience the confusion occurs when switching back to an Ai or later lens. It's easy to forget to pop the Ai tab back into position, at which point you'll mysteriously lose all aperture control until you figure out your mistake.
The verdict? Old lenses are entirely practical for use on the Nikon Df. Its resolution is not so high that accurate focus becomes too tricky, mechanical support for lenses in the Nikon F system is almost universal going right back to the late 1950s, and there are a lot of really excellent older lenses out there which have a lot to offer on today's DSLRs. My personal current favorite is my mid-60s 105mm F2.5 (see above). Originally a pre-Ai lenses it was converted to the Ai standard at some point, and delivers excellent results without taking up a lot of space in my camera bag. And, better still, it cost me less than $100. Let the Ebay trawling begin!