No focus motor for D5100 means what?

Discussion in 'Nikon' started by alan_markowitz|1, Jul 14, 2011.

  1. Hi All,
    I'm reading reviews of the Nikon D5100 and while I see that it's a wonderful camera, the camera does not have a focus motor (like, for example, the D7000 which has a built-in AF motor).
    In practical terms though, what does that mean? Will it not focus the lens? Will it focus more slowly? What, if any, are the effects on performance, speed, etc.
    Thanks for the help!
  2. ShunCheung

    ShunCheung Administrator

    If you want auto focus, there has to be a motor to drive the focus, either inside the camera or inside the lens. For those Nikon DSLRs that have no AF motor in the body, such as the D40, D3100 and the D5100 you are interested in, you must use a lens with an AF motor inside the lens for you to get AF; among Nikon lenses, that means you need to use AF-S lenses.
    If you use an older AF/AF-D type lens that has no AF motor iniside the lens, you'll have to focus manually with a D5100 camera body.
    Since essentially all Nikon AF lenses are AF-S lenses in these days, this is largely a non-issue. I have like 25 Nikon lenses and only 1 or 2 I use have no AF motor, such as the 10.5mm DX fisheye. Incidentally, that is the only DX lens that is not AF-S. However, some recent 3rd-party lenses are not AF-S, such as Tokina's 11-16mm/f2.8 wide zoom.
  3. "essentially all Nikon AF lenses are AF-S lenses in these days" - is it really ?
    In current NikonUSA offering there are AF lenses, and if you are not careful, it could be an issue for you with D5100 camera,
    In list of all 76 Nikon lenses, there are about 30 or so AF or M lenses, that you would need to focus manually on D5100.
    from more recent offerings,
    e,g. 2 of current offering from "Travel and Landscape" lenses are AF:
    also 2 from "Sports and Action Lenses" are AF lenses:
    If you can focus fast manually, an AF lens or M lens focused by yourself, could be faster than the AF-S lens, but usually it is much slower and less acurate.
  4. if you buy the camera with a lens in the box -- called a "kit lens" -- you will go along happily shooting, and not give a thought to this matter of in-body focus motor. that is, until you get into the hobby, and at some point are seized by the notion of adding a lens (or lenses) to your kit for certain kinds of more-specialized photography. then, for example, you may become interested in a fast, long zoom like the 70-200 f/2.8. upon seeing the $2,300 price tag, however, the 80-200 f/2.8 lens in nikon's catalog, with it's more reasonable $1,100 price, might be attractive. then you find out, sadly, that the 80-200 lacks that focus motor thing -- meaning you either accept manual focus, or you move on to other options. on the bright side, nikon is filling the gaps that have existed in its product line, with items like the recently announced 50mm f/1.8 AF-S lens, where previously only a screw-driven lens was available before. in brief, lack of a focus motor will limit the usefulness of a lot of older lenses, while the availability of newer replacements is getting better.
  5. Thanks for the input.
    Given that the D7000 has a built-in AF motor, will it focus even faster when mounting an AF-S lens (i.e. two motors)?
  6. Alan, No it will not focus faster because two motors. The motor in the body uses "screwdriver" coupling to run AF lense's AF. AFS lenses have their own built in motors and they run AF. Two motors does not give you faster auto focus.
  7. Given that the D7000 has a built-in AF motor, will it focus even faster when mounting an AF-S lens (i.e. two motors)?
    No, at least not for that reason. When an AF-S lens is mounted, the built-in AF motor does not operate.
    However, a Dxxxx may autofocus a specific AF-S lens faster than a Dyyyy because the Dxxxx has a better autofocus module (ie. faster hardware/software) than the Dyyyy. I don't know if that is the case for the D7000 vs. D5100.
  8. Hi Alan. No, but yes. :) The second motor in the camera doesn't make a difference to the autofocus speed if there's already one in the lens - it isn't connected to anything. However, higher-end cameras do have more advanced autofocus systems, and the D7000's is much more capable than the one in the D5100 (particularly when it comes to the subject movng around the frame) - so the D7000 have better autofocus than the D5100, but not because it has a motor. If you just focus in the middle of the frame, however, it's probably not much faster as such, it's just better at keeping hold of a moving subject and more flexible about where in the frame you focus.

    There are even higher-end Nikon cameras that can focus AF-S lenses faster, because they can supply more current to the lens's motor, but these are the large professional cameras (the D3 series) with bigger batteries. Unless you're a professional sports shooter, I wouldn't worry about it - most AF-S lenses focus very quickly anyway.

    I hope that helps, and that providing a complete answer hasn't just confused matters!
  9. Thank you all VERY much. It certainly helps a lot.
    Just to touch on one point Andrew wrote, if I use a battery pack with two batteries, will that make the focusing in the lens faster, because there is more power?
    Thanks again.
  10. Alan -
    No - 2 batteries will not improve the AF speed. It may increase the frame rate slightly, but the AF speed is dictated by the AF motor and the lens.
  11. Sorry to have caused more confusion - as David says, the professional bodies can focus faster because they have a different power system. A battery pack on a low end camera mostly gives you longer battery life (and something to hold it by), and for some models improves the frame rate, but won't affect the autofocus.

    Perhaps it would help if I asked why you're concerned about focus speed, and what performance you're expecting? Any DSLR and almost any AF-S lens ought to keep up with moving children, for example, whereas if you're tracking a moving soccer ball from behind the goal posts, the pro equipment might actually matter.
  12. ShunCheung

    ShunCheung Administrator

    Since this thread is about the D5100, please keep in mind that Nikon themselves makes no battery pack/vertical grip for the D5100. Any such grip you may find is made by 3rd parties.
  13. ...the professional bodies can focus faster because they have a different power system.​
    Another case of someone competing for smartest person in the room award and winding up wearing their rear end for a hat.
    If a pro body focuses an AF-S lens faster than a consumer body, it's because it has a better AF system, not because it spins the motor faster. The focus motor in an AF-S lens rotates at the same speed regardless of what body it is attached to. It doesn't matter how much current the battery can source because the motor will have current limiting devices to prevent it from overheating.
  14. Bruce: I refer you (and Alan, since the thread might apply to his query) to this discussion, in which Joseph claims that the Nikons with 11.1-volt battery systems (currently the D3 series, or a D300s/D700 with a battery grip and an EN-EL4a installed, I think) allow the lenses to focus faster than those with 7-ish-volt batteries. I have to trust to Joseph's apparently intimate knowledge of the F mount (which has thus far proved reliable); I've not performed an experiment myself, and don't own a battery grip for my D700 with which to do so. Given the distributed area of an AF-S motor and the relatively low weight that it has to move, I doubt overheating is a major concern with normal battery power. But I could be wrong; Bruce - if you have detailed knowledge of the AF-S control system for the F mount, I will humbly be interested in being corrected.

    I provide this information partly because Alan seemed curious about absolute focus speed, as opposed to the flexibility of the autofocus system, and because people who want detailed information might come across this thread. I'm not competing for anything, because on this forum there are people who know much more than me, but I'm trying to be precise and save the experts from having to type in every thread.

    More recent cameras tend to have faster autofocus, partly because the processing is improved. A D7000 might beat the D5100 even if they're both using cross-type sensors, depending on how much the D5100's autofocus module has been upgraded since similar technology was first introduced a few years ago, but I'd actually not be surprised to find it was close; the D7000's big benefit in autofocus is the flexibility of the system and number of autofocus points - there's only so much processing to do in the lens ballistics and phase detection. I could be wrong here as well, and would be academically interested in measurements. Can a D3s focus faster than a D3100? Almost definitely - partly because of the advanced autofocus system, partly because of the extra power. Would a D7000 (which has a very modern AF system) with a battery pack focus as fast? I doubt it, because even with the battery pack the D7000 can't provide the same power to the lens as a D3, and at some point what's limiting the focus speed is how fast you can accelerate a bit of glass.

    If Alan actually wants to know what the fastest-focussing Nikon camera is (since he wanted to know about battery packs for improving performance), I suspect the answer is a D3s, which may or may not tie with the older D3x, D3 and D700/D300s-plus-battery-pack. I have no idea whether a D7000 can get an AF-S lens into focus any faster than a D5100; the D7000's autofocus system is indubitably better, but I wouldn't like to guarantee that it's faster per se.

    I doubt any of this has as significant an effect of focus speed as the choice of lens. I would assume that Alan wants a low-to-mid-end camera with reasonable autofocus performance, in which case: either will do fine, and the D7000 is more flexible. However, if he really wants to know about focus speed as such, and he might, I hope this post provides more than enough information. We might be able to give more specific advice if we know why he's asking.

    Just trying to be helpful, if I can still see the screen to type from my position under my posterior.
  15. Joseph Wisniewski states the following:
    ....cameras with higher drive voltages always beat cameras with lower voltages, whether it's a screwdriver lens or an internal motor lens.​
    The Silent Wave Motors Nikon uses in their AF-S lenses are ultrasonic motors. You can find information on them at wiki:, NASA: or Utube:
    Not much about voltage in those links, because they don't address much about the drive electronics in ultrasonic motors. In fact, the motor isn't directly driven by the DC out of the camera body. It's driven by a high voltage, high frequency driver circuit. There's a nice paper covering ultrasonic motor control here:
    In the conclusion of the paper was stated: The speed of the USM was primarily
    controlled by the driving frequency.
    Designing the motor control circuits to work at two different voltages adds complexity and doesn't add performance. Think about it: why would Nikon add expense to consumer grade, AF-S lenses for them to run faster on bodies that they would hardly ever be used on? The answer is they don't. Lastly, I have never read, or heard of anyone like Thom Hogan, Bjorn Rorslett, or our own Ellis Vener suggest or state that pro bodies run AF-S motors faster.
    If somebody thinks something else, provide sources and references. I'm getting tired of told to me by a gypsy.
  16. I appreciate that we've wandered off-topic, but this might come up when someone searches for this information, so I'd like to continue for now...

    Bruce: I can only say that I'm reporting what Joseph has said, that his information on Nikon hardware has so far been authoritative, and I've never seen that statement contradicted - nor seen any of the luminaries you mention discuss the relative focus speeds of different bodies. I've asked (I hope; I never get on with the message system) Joseph whether he'd be kind enough to comment directly.

    My understanding - again, based on information provided by Joseph, this time here - and difficult to confirm because the F-mount pinout is proprietary (this thread is informative, and Joseph's suggestion of US patent 4896181 seems to be contain useful information) is that the F mount contains a low regulated voltage (Vcc) and a higher unregulated voltage (LBAT). The microcontroller in a lens would run off the regulated voltage; the battery voltage would be available for the motor drive circuitry, and quite possibly would have no need to be any fixed voltage (withing reason).

    Appreciating that I have a limited knowledge of both ultrasonic motors and speed controllers in general, I would expect that the speed of the motor would be controlled - as you say - by the drive frequency. Indeed, we know that modern autofocus systems predict the time it takes to accelerate their components in order to optimise the speed of arrival at the focus point - they are, in part, open-loop. The controller in the lens will be ensuring that the focus elements move at a tightly-controlled rate.

    What I would expect to depend on the input voltage is the torque of the motor; indeed, that supposition is discussed in this paper: "In an ideal ultrasonic motor...the maximum torque increases in proportion to the input voltage...Therefore, to increase the input voltage becomes expedient for torque augmentation". I have no idea whether the relationship between the battery voltage and the SWM operating voltage is direct, and how the power available through the larger battery translates to motor torque, but I'm entirely prepared to believe that a camera body with a larger battery can apply more torque when accelerating lens components, which would translate to increased overall performance of the autofocus system. The same, of course, applies to lenses with a conventional motor on board, which use the same interface.

    I don't claim to know for sure how the mount or motor drive systems that Nikon use work. As I mentioned, I'm in no position to time some lenses, although I guess I could measure LBAT from my F5 and D700 and try to confirm that the voltages are different, if needed. But the fact that Nikon's cameras use more than one battery voltage (sometimes in one camera - there's a discussion of the MB-D10 here that talks about the increased voltage improving the camera functionality, but doesn't mention focus speed) would seem to be something that the lenses can use as well.

    I hope Joseph can be more definitive - or someone with a D700 or D300 and an EN-EL4a/MB-D10 combination could do some timings. I don't mean to sound argumentative to Bruce (or make him tired!), but all the evidence I've seen backs up the assertions that Joseph has made. I think I've here reached the end of my limited knowledge of electromechanics, so I'll have to pass this line of reasoning on to someone who actually claims to know what they're talking about.
  17. D40, D50, D60, D3000 series & 5000 are not having servo motor for focusing and hence you have to use lenses with built in motor and it is marked as G lenses so you can get AF in the mentioned bodies
    However, if you have old lenses that is marked as D lenses then you need servo motor in the body
    such as D100, 200, 300, D1, D2, D3, F5, F6 etc.
    The servo motor couple a small screw driver type needle into the lens and do focusing which is normally slower than G lenses that are AF-s "Auto Focus Silent" similar to USM in canon or HSM in sigma which they are all faster than D lenses
  18. Abbas - your terminology is slightly confused; just to clarify:
    • AF-S (and the much rarer AF-I) lenses have motors in them and will autofocus on bodies without integral autofocus motors.
    • Lenses that are "AF" but neither "AF-S" nor "AF-I" need a motor in the camera to autofocus.
    • "AF-D" lenses tell the camera the focus distance, which makes a minor difference to metering (especially with flash). Most "AF" lenses, except very old ones, are "AF-D". All "AF-S" and "AF-I" lenses also have this ability.
    • "G" lenses just don't have an aperture ring, and rely on the camera to set the aperture. This has nothing to do with autofocus - there are AF-S lenses which are not "G", and AF-D lenses that are "G". Most new lenses are "G", but several current lenses aren't. There is no advantage to a lens being "G" (it saves money); on a modern camera there is little disadvantage to being "G".
    • Large AF-S lenses are usually faster than the screw-drive autofocus versions. This is not always true for the smaller lenses (such as the 50mm primes) - but the slower AF-S lenses aren't much slower and are usually more reliable at hitting focus than the AF-D versions.
    • Nikon still sell a number of AF-D lenses, some of which have no true AF-S equivalent, but newly-announced lenses are generally AF-S.
    I hope that helps clear things up.
  19. ShunCheung

    ShunCheung Administrator

    I have had my D300 for about 3.5 years, almost since as soon as it was available, and I bought an MB-D10 battery pack at the same time along with the D300 body. I have use 8 AA batteries and EL-EL4 batteries inside the MB-D10 to power the D300 and my D700.
    Joseph Wisniewski has pointed out that you need the higher voltage to run the entire mirror/shutter mechanism faster to achieve 8 frames/sec on the D700 with the larger mirror for FX. However, it is news to me that the higher voltage will make AF-S faster. I haven't noticed any difference myself. There could be some difference, but at least to me, it is not obvious.
    In any case, since Nikon provides no battery pack option for the D5100 in the first place, I wonder how you can provide a higher-voltage to the D5100, and would that damage the camera? To me, the whole debate about higher voltage seems to be totally moot and off topic in the context of the D5100.
  20. Shun - thanks for your sample point. I'm prepared to believe that Joseph is wrong about this (or that I've misunderstood hiim) - I hope he contributes.

    I agree that we've wandered off topic; I was merely trying to provide a complete answer to Alan's query about whether an in-body motor improves performance, by stating something that - I believe - does improve performance, and wanted to be sure that we'd covered everything Alan might want to know; Alan did also mention the D7000, which does have a battery pack (but which doesn't change the voltage available, unlike the D300/D700 model). I hope you, and Alan, will indulge us long enough to get a brief clarification (from Joseph or someone else who claims definitive knowledge one way or the other) on this final point, since we've come this far in asking the question.

    Alan: There's always more to learn... :)
  21. Bruce Robinson - Another case of someone competing for smartest person in the room award and winding up wearing their rear end for a hat.​
    Definitely. But why are you bragging about it?
    Nikon cameras with higher operating voltages, like the 11.2V D3, do order higher stepping rates from the piezo motors than the 7.4V cameras like D7000 or D90. You can see this on a protocol analyzer after breaking out the data lines at the lens mount. You can also check the lock-to-lock timing for a hunting lens on different voltage cameras.
  22. Joey baby, when you learn how to copy and paste someone's name so it's spelled right I may take you seriously.
    A protocol analyzer does not measure the AC voltage level coming out of the drive electronics that powers the motor.
    Hunting for focus is dependent on numerous factors. Come back when you taken a class in control theory.
  23. There are a number of things that affect focusing speed.
    The two primary things are
    • The capabilities of the AF system in the camera.
    • The speed and accuracy of a particular motor and lens at driving that lens's focusing group.
    The camera's AF system has to determine about how far the current lens position is from being in focus, and how far the lens has to be moved to get it in focus. It may also have to analyze multiple focus sensors and determine which of them actually contains the "subject", and which direction the subject is moving, relative to the camera.
    Moving the lens the required distance isn't an easy task. Each lens has a "ballistics table" that tells the camera all sorts of stuff about the lens. For a screwdriver lens, each lens is geared differently, so the table tells the camera how many degrees of barrel rotation you get from a certain number of degrees of screwdriver rotation, and how much focus change you get at different barrel positions. (there's actually an interpolator table, because the classic 1/f=1/a+1/b rule only applies to "unit focusing" lenses like the 50mm f1.8, while most of the Nikon line is front focusing, rear focusing, or internal focusing). The ballistics tables also include information on the lens's backlash. If you turn a lens in one direction via the screwdriver, then reverse the motor direction, there's a certain amount of screwdriver rotation while you go from the clockwise faces of a gear's teeth being in contact with the counterclockwise faces of another gear's teeth, to the opposite position.
    More annoyingly, the camera's own AF motor has a geartrain with backlash of its own, so the camera has to know how to combine the two. There's also some stuff in the ballistics tables about inertia, so the camera can calculate how fast it can accelerate particular lens, and how much the lens is going to coast after the camera shuts down the motor.
    AF-S lenses are easier, because there's essentially no backlash in the ones with a ring piezo motor, and much less backlash in the ones with a small geared piezo motor. And, the lens just needs a simple table of motor speed vs. voltage. Yes, the lens converts voltages, but the power that it has access to is determined by the voltage supply in the camera. (From what I've been able to determine, Nikon makes the rather silly assumption that all cameras can supply the same amount of current).
    Note that the camera doesn't always move a lens at that lens's maximum motor speed, because sometimes the camera calculates that the AF sensors won't be able to provide useful information with the lens moving full speed. This is most common on wide angle lenses.
    So, the overall answer is "it's complicated". Some lenses have small, inexpensive geared piezo motors, and a camera with a large, fast internal motor will focus a similar "motorless" lens a lot faster. Tamron's 24-75mm is one of my favorite examples, a D3 can whip a screwdriver version of that lens around a lot faster than the motorized version. Some lenses have so much better (well tuned, optimized for that lens) AF-S motors that the AF-S version always focuses faster than a screwdriver version. Compare an 80-200mm AF-S on a D70 to a 80-200mm AF-D two-ring, the AF-S wins. Put both lenses on a D3, and the AF-S still wins. That lens design is so "amicable" to AF-S motors that they always win.
    Basically, there are 4 totally independent variables, the age of the camera, the place it occupies in the Nikon line, the voltage of the camera, and the type of AF-S implementation...
    • newer cameras focus lenses faster and more accurately than older cameras in roughly the same class. Same AF-S lens on a D60 and a 5100, no contest, the 5100 wins.
    • higher end cameras focus lenses faster and more accurately than lower end cameras of the same age and voltage.
    • higher voltage 11.1V cameras focus lenses faster than 7.4V cameras from the same period.
    • cheap AF-S lenses focus slower than similar screwdriver lenses when used on the same camera, or comparable cameras.
    • expensive AF-S lenses focus faster than similar screwdriver lenses when used on the same camera, or comparable cameras.
    So, if it's a simple question, like "How does a D5100 compare to a D7000 when used with a 35mm f1.8 AF-S", you've only changed one variable, the class of the camera, and the answer should be "the D7000 will be faster and more accurate".
    If it's a complicated question, like "How does a D5100 with a newer motorized Tamron 90mm f2.8 macro compare to a D7000 with an older non-motorized macro", you've just changed two variables, the motor type and the AF system type, and there's no easy answer.
    But one thing I can add. The "multi-voltage" cameras (D100, D200, D300, D700) still only operate at 7.4V when you put two EN-EL3e batteries in the grip. The only way to get them to higher voltages is to put 6 1.5V AA batteries in the tray, or an EN-EL4 (D300 and D700 only). The camera does not appear to tell an AF-S lens that it has a higher voltage, so the AF-S lens uses drive rates appropriate for a lower voltage. The "charging" (shutter and mirror) and internal AF (screwdriver lens) motors do operate at a higher speed.
    Third party grips on cameras that aren't built for grips always provide the low 7.4V, so this is not an issue for cameras like D5100. There is no way to make such a camera go faster.
  24. Joey baby​
    It's really amazing that there actually are people in the world that are so dull witted that they would start a post like that and expect anyone to read anything past that point.
  25. "essentially all Nikon AF lenses are AF-S lenses in these days" - is it really ?​
    Yes, Frank, it is. Really. "Essentially all".
    You give examples like 2 of the 24 lenses on the "Travel and Landscape Lenses" page and 2 of the 28 on the "Sport and Action" page being screwdriver. Did you actually look at what lenses those were?
    • 10.5mm fisheye, an enormously popular lens selling about 800 units/year. And one that doesn't need much focusing. It's also on both pages, so you've really got 3 lenses, not 4.
    • 24-85mm f2.8-4, a lens launched back in 2000 as a "kit zoom" for film cameras, with a reputation as an underperformer, and slow sales for a lens in its class of just 12,000 units/year. Look at any "kit zoom" for the cropped digital cameras. The cheap ones radically outsell it, like the 18-55mm f3.5-5.6 VR at 1,555,000 units/year, or even the old 18-70mm f3.5-4.5 at 320,000 units/year. The expensive ones also outsell it, like the 17-55mm f2.8 at 27,000 units/year or the 24-70mm f2.8 at 84,000 units/year.
    • 80-400mm f4-5.6 AF VR. Another woofer from Y2K for you. It sells at a brisk 13,000 units a year. $1,849 MSRP, I bet D5100 owners are lining up around the block to get their share of the low 80-400mm production.
    So, I'd say Shun nailed it. "Essentially", as in the only lenses that aren't AF-S are a very low selling specialty lens (that may have been discontinued years ago. If they ran them 5,000 at a time, and sell 800 a year, it takes over 6 years to sell out a production run. That's the way specialty lenses work). Or the lens that may have been the biggest failure as a "kit zoom" and telephoto zoom in Nikon history. The lenses in the "Travel and Landscape Lenses" page and "Sport and Action" pages represent about 6 million units/year, and your examples are 0.4% of that. 99.6% of the lenses produced are AF-S, which I'd sure call "essentially all".
    Shun's "essentially" beats Ivory Soap, at "99.44% pure".
  26. Frank missed a few, LOL...
    • 14mm f2.8, a hot 1,700 unit/year lens, about the same price as the much better performing 14-24mm f2.8, which flies out Nikon's doors about 20x faster, 30,000 units/year. (I used to have both. Guess which one I kept).
    • 16mm f2.8 fisheye. A $999.95 lens that only makes sense on FF: D3, D3X, D700, or film.
    • 18-35mm f3.5-4.5, a 10 year old lens designed as a cheap ultrawide for FF, but for a DX camera, one gets better performance from the smaller, lighter 18-55mm f3.5-5.6 VR at 1/5 the price. Maybe that's why the old screwdriver lens has sold 1,300 units/year since 2008, while the AF-S VR moves at 1.5 M units.
    • 20mm f2.8. Mine's for sale, anyone interested? Fair warning, the 18-70mm and 17-55mm are better on DX, the 14-24mm and 17-35mm are better on FF.
    • 24mm f2.8. See 20mm f2.8.
    • 28mm f2.8. It's famous, for all the wrong reasons. (Although I sort of liked it as a normal on APS).
    • 35mm f2.0, slower, larger, and twice the price of a higher performing DX 35mm f1.8.
    • 50mm f1.4, although still in stock, one doubts it's actually still in production, seeing as there's also a AF-S version.
    • 50mm f1.8, see 50mm 1.4
    • 60mm f2.8 AF-D micro-Nikkor. See 50mm f1.4. Although I head that Nikon actually decided to launch the AF-S while there were an estimated 20,000 in distributor and dealer stock, causing no end of grief.
    • 70-300mm f4-5.6. That niche sort of gets split between the more versatile (but more expensive) 55-300mm f4.5-5.6 VR and the 55-200mm f3.5-5.6 at the same price.
    • 80-200mm f2.8 two ring. Well, it's cheaper than a 70-200mm f2.8 AF-S VR II...
    • 85mm f1.8. A small, light portrait lens, 128mm f2.7 equivalent in terms of coverage and DOF, it's a little gem, and probably the only lens on this list that's actually a serious hole in the line.
    • 105mm f2.0 DC, a $1000+ "portrait lens" that is out of production, despite being listed on the Nikon "all lenses" page. At 157mm equivalent, a bit long and without purpose on a DX, anyway...
    • 135mm f2.0 DC, see 105mm f2.0 DC.
    • 200mm f4 micro-Nikkor. A low production, highly specialized $1729.95 lens.
    So, while Frank missed a lot of lenses, nothing here alters Shun's assertion that "essentially all" the Nikon line is AF-S. There is exactly one lens, the 85mm f1.8, that isn't an over $1000 specialty lens or is something that there's a better performing AF-S alternative in the same price range. I'm not sure if you add up the total unit sales of everything on this list, it amounts to 1%.
  27. Joseph: Thank you for contributing; I must now apologise for ever having said more than "it's complicated" when it comes to speed of focus differences between bodies.

    I would still be interested to see some timings between different class bodies of the same generation, because I don't really see what there is about (say) a D7000's autofocus system that should make it any faster than a D5100 if they're both using an optimal (cross-sensor) focus point, but that's just because I'm curious. Maybe the D5100's system is genuinely older, or maybe it's deliberately crippled for market placement reasons. The D7000's autofocus is definitely better, however. For Alan's sake, I can state that my means of using the camera changed drastically between using a seven-point sensor (on an Eos 300D) to the 51-point sensor on the D700; more focus points can matter.

    Since I'm likely to refer back to this thread... Joseph: are you in a position to state the source of your expertise (or at least your information in this case)? I'm a software engineer working on embedded microprocessors and I spent an abortive period contemplating the robot wars scene; I know the basics of motor controllers and control protocols in general, but I've never waved an LA at a Nikon body and don't claim any specific knowledge. I get the impression you've done some reverse engineering - there are obviously a number of third party manufacturers using the F mount. Bruce has not stated why he is so sure of himself that voltage is irrelevant (so Bruce, this applies to you as well), but - other than not having been misled by one of your posts yet - whenever two people who claim to know their field are in disagreement, it's nice to distinguish the authority with which they speak.

    To pick up on "essentially all"... there are some important lenses that are screw-drive only. The 135 f/2 DC is one reason I switched from Canon, for example, and the 80-200 holds a significant market point. But I concur that the vast majority of lenses sold, and indeed desired, are likely to be AF-S.

    Thank you for the information - and Alan (and Shun) sorry for subverting the thread. I'll try not to elaborate on any details that could be swept under the carpet next time...
  28. ShunCheung

    ShunCheung Administrator

    "essentially all Nikon AF lenses are AF-S lenses in these days" - is it really ?​
    It is my fault that my wording wasn't very precise. What I meant was that all new AF lenses Nikon introduces are AF-S nowadays. The last screwdriver AF lenses were the 50mm/f1.8 AF-D and 10.5mm/f2.8 DX AF-D from 7, 8 years ago.
    If you check Joseph's list, the 50mm/f1.8 AF-D, 50mm/f1.4 AF-D, 60mm/f2.8 AF-D macro, 70-300mm/f4-5.6 AF-D ... have all been superseded by AF-S versions. There should be little doubt that those lenses are effectively discontinued; only some old stock is remaining. The other remaining ones are pretty old AF lenses from about 20 years ago or more.
    The real issue is that while Nikon has stopped introducing AF-D type screwdrive lenses, the likes of Tamron and Tokina have continued to do so. If you buy a D3100 or D5100, they will not AF with some fairly recent lenses such as Tokina's 11-16mm/f2.8.
  29. The real issue is that while Nikon has stopped introducing AF-D type screwdrive lenses, the likes of Tamron and Tokina have continued to do so. If you buy a D3100 or D5100, they will not AF with some fairly recent lenses such as Tokina's 11-16mm/f2.8.​
    Indeed - my Sigma 8mm f/3.5 fish-eye is also screw-drive, to give another example. Since the third parties are usually trying to undercut Nikon's prices, I guess they may sometimes have to do so by omitting the in-lens motor - in several cases there's a price difference between the Nikon (screw drive) and Canon (integral motor) versions. And, of course, much of Nikon's older lens line are perfectly adequate and available cheaper screw-driven. Save money on the body, lose money on the lenses. This is true further up the range as well - only the higher-end bodies can meter with the very cheap (relatively) Nikon AI non-autofocus lenses, and the only current camera with full support for pre-AI lenses is the top-of-the-(film-)line F6 (with an adapted ring). Backward-compatibility is a premium feature. Which may not matter if you're happy with a small number of recent lenses.
  30. OK, I am a little confused, would appreciate ff someone can clarify. I guess from the responses that the closest equivalent to 50mm 1.4D is the 50mm 1.8 AF-S, is that right? I have a D70, 50mm 1.4D is pretty much the only lens I use. 90% of my pictures are indoor available light with flash on slow speed sync (i am horrible with flash), I think I will miss the added larger aperture on the 1.4. What are my options?
    1. should I get a body that will take 1.4D, which is the cheapest body that will do it?
    2. should i just get the 5100 and use 1.8, is the new systems grain at high ISO low so that i don't have to have a larger aperture?

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