One of the hallmarks of the Nikon System is its compatibility within and between its various generations. Whilst this compatibility is sometimes limited only to the ability to mount and shoot with a particular lens, it is nevertheless a definite advantage if you are on a budget or seek to explore some less orthodox techniques and styles.
Broadly speaking, Nikon's range of F-mount lenses can be broken up into eight generations for the purposes of assessing compatibility.
(If you feel pretty confident about this stuff, feel free to skip to actual answers)
|Pre-AI (also Non-AI, N-AI)||These lenses are from around 1959 to 1978, and were originally intended for use with the original F-mount bodies, the F, F2, and Nikkormats. They are fitted with a prong that couples with the Photomic metering systems used by these cameras.|
|Pre-AI Invasive Fisheye||Prior to the introduction of retrofocus optics, fisheye and other ultra-wide-angle lenses were very complicated to design. Nikon got around this by designing them so that the back of the lens reached back into the camera, almost touching the film. These lenses can only be used on certain film SLRs, as they damage the reflex mirror without special settings.|
|AI / AI-S||'AI' lenses were introduced from 1977 onwards, featuring a new system of meter coupling that simplified the process of using the lens with the camera's meter. This is the first range of lenses that is widely compatible with all Nikon SLR cameras. AI-S was a revision made in 1982 to refine operation of the Program and Shutter-Priority Autoexposure modes on the FA.|
|AF / AF-D||Nikon's first autofocus lenses (excluding the special lenses for the F3AF, which aren't covered here) were released in 1986, specifically marked "AF Nikkor". These lenses are fitted with a Central Processing Unit, which transmits information about the lens electronically to compatible bodies. The lens elements are automatically focused though a coupling with a focus motor in the camera body. AF-D lenses, denoted by a 'D' after the aperture value on the lens (i.e. "AF Nikkor 35mm 1:2D"), were a later revision that enabled slightly better exposure by informing the camera of the distance at which it is focused.|
|AI-P||This further revision to the AI standard was made in 1988, and is an oddity in that such lenses are manual-focus lenses, but with the CPU and electronic connections of an autofocus lens. This enables full metering functionality on all Nikon SLR cameras. Only a few lenses were ever released in this specification, mostly super-telephotos, and are denoted by a P after the aperture value.|
|AF-I / AF-S||AF-I was introduced in early 1990s in professional lenses where the standard autofocus drive was found to be too weak and/or slow. This was rectified by placing a focus motor inside the lens body and directly coupling it to the focus helicoid, but it came at a price of increased weight and cost. It was replaced a few years later by AF-S, which uses a Silent Wave Motor (similar to Canon's USM) wrapped around the helicoid to move it quickly and quietly. Instant manual-focus override is available on AF-S lenses. All AF-I and AF-S lenses are otherwise electronically identical to AF-D lenses.|
|AF-G||AF-G lenses are autofocus lenses that have had the aperture ring removed to allow easier operation on autofocus cameras and to save costs. They are denoted by a G after the aperture value. G-lenses may be AF or AF-S, but have the distance-communication electronics of AF-D lenses.|
|DX||Lenses with images circles that only cover DX-format digital sensors, introduced in 2003. Nikon justified this by saying that it allowed for a reduction in the size, weight and cost of the lens. Marked "DX Nikkor", these lenses will mount on film SLRs, but may not render a full image on the frame.|
If you're not sure what type your lens is, check our Lens Identification page.
With that aside, we can now asses the three categories of compatibility: mounting, metering, and autofocusing.
Will it Mount?
If it's a F-mount lens, and it's not an invasive fisheye, then it almost certainly will.
|Designation||Mounts on D40-series?|
|AI / AI-S||Yes|
|AF / AF-D||Yes|
|AF-I / AF-S||Yes|
This question is a lot simpler than the other two. Can you put the lens on the camera?
This is where the D40 gets to shine. The D40 will mount pre-AI lenses, the original lenses for the Nikon F and F2 that, because of a small but significant difference in design, would break most other Nikon SLRs if you tried to mount them.
This is good, because it gives you access to a lot of very, very inexpensive old lenses from the pre-autofocus days. You'll have to focus manually, shoot in manual (M) mode, and guess the aperture and shutter-speed combination. This way of shooting is not for everyone, but it won't cost you much to pick up a fast 50mm like the pre-AI Nikkor-H 50mm 1:2, which can cost less than US$50, and give it a try.
A caveat though about any old lens: always exercise caution when mounting a lens that you haven't tried before. Whilst experience tells us that in almost every case you'll get away with it, common sense tells us that there are lenses out there with different characteristics to what we expect.
Will it Meter?
If the lens has a CPU, it will meter. This means AF or later (AF-D/AF-I/AF-S) lenses will meter, as will AI-P (manual focus lenses with metering chip). Most third-party equivalents will also meter.
|Designation||Meters on D40-series?|
|AI / AI-S||No|
|AF / AF-D||Yes|
|AF-I / AF-S||Yes|
What's metering? Metering is what enables your camera to look through the lens and tell how much light is hitting the scene. This lets your camera work in autoexposure modes including aperture-priority (A), shutter-priority (S), program mode (P), and so on. It also allows the use of Auto-ISO, and provides you with a a guide to proper exposure when in manual mode.
The D40 will meter with any CPU lens - those that bear AF, AI-P, AF-I, or AF-S markings.
The D40 will not meter with any manual-focus lenses other than AI-P versions. In this respect it is the same as Nikon's other consumer DSLRs, like the D50, D70, D80, D90, and so on.
Will it Autofocus?
Only lenses with built-in focus motors will autofocus on a D40. This means Nikon AF-I or AF-S, Sigma HSM, or Tamron N-II. This list shows specific lenses.
|Designation||Autofocuses on D40-series?|
|AI / AI-S||No|
|AF / AF-D||No|
|AF-I / AF-S||Yes|
Most Nikon autofocus camera bodies have a motor built in to them which allows them to drive older "AF" lenses through a coupling in the mount. To save weight and money, the D40 does not have this motor, so it can't autofocus those lenses. Newer AF-I and AF-S lenses have these motors built into them, so the D40 can autofocus them.
Is this a problem? Depends. If you'll spend most of your time using the kit lens, possibly in conjunction with a telephoto-zoom like the AF-S DX Nikkor 55-200mm 1:4-5.6, then it won't be. Most of Nikon's cheaper zoom lenses are designed to autofocus on the D40.
It might become an issue, though, if you want to branch out and start exploring Nikon's wide range of superlative optics, including the excellent - and quite cheap - selection of now-discontinued or superseded lenses. Most AF-I and AF-S lenses until just a few years ago were aimed at the professional market, and it took Nikon a little while to get around to updating their lower-volume lenses. This means that if you want, for example, a 35mm 1:2 or 80-400mm 1:4-5.6, you'll have to get it as an older model - and manually focus it on the D40.
Also, until recently, third-party lens manufacturers didn't make much of an effort to build focus motors into their Nikon-compatible lenses. Sigma now market several lenses with internal motors, which they mark "HSM", as do Tamron (marked N-II). Tokina is adding a focus motor to its 12-24.