33

Like many things when it comes to designing hardware for photography, there are always tradeoffs to be considered and made. STM lenses sacrifice a little speed in order to be quieter and smoother (no jerky starts and stops). This is important when using Autofocus while recording video. Lenses with USM focus designs are built for speed first and quiet ...


29

No Canon EOS body needs AF motors because every single Canon EF lens released since the EOS system was introduced since 1987 has a focus motor in the lens. Thus no Canon EOS camera has ever had a need for a focus motor in the body. There are a few manual focus lenses in the EOS system, but they are clearly designated as such by not being named as an EF lens:...


25

Your old D80 had a focus motor built into the body that connects to a mechanical coupling on Nikkor AF lenses to move the focus elements in the lens. Your D5300 does not have a focus motor in the body. To use autofocus your D5300 requires that you use Nikon AF-S or AF-I lenses or the equivalent third party lenses (such as Sigma's HSM or Tamron's USD and PZD ...


17

There are three parts to the answer to this, which is appropriate, because with Sony, Olympus, Panasonic, Fujifilm, and Sigma focusing on mirrorless designs, there are really only three companies making DSLRs: Pentax, Canon, and Nikon. First, all Pentax DSLRs, even the entry-level models, have built-in autofocus motors. So, if that's really your main ...


16

USM is fast, STM is smooth. For still images (particularly with sports and wildlife) it is important that focus tracks quickly whereas in video the quick movements of a USM lens make the video feel jerky.


15

No Canon EOS camera has an in-body focus motor. Canon's lens mount is 100% electric, there is no mechanical linkage. (Some mounts e.g. Pentax have a mechanical link for the aperture too, for some lenses). The EF designation of Canon's lenses stands for Electro-Focus - in other words, the focus is driven electronically. Each lens has a built in motor. There ...


12

Nikons with autofocus motor in body: D50, D70, D80, D90, D100, D200, D300, D7xxx, D6xx, D7xx, D8xx, all pro models (D1, D2, D2, D3, D4, Df). Models derived from those (e.g. D300/D300s, D3/D3x, etc.) also have AF motors. Nikons without AF motors: D40, D60, D3xxx, D5xxx. I think a D90 would make an excellent upgrade to you D3000. All the bodies with AF ...


10

Canon autofocus lenses have long focused on speed and not so much on smooth and quiet operation. This is what we know today as USM (Ultrasonic motor). As usage of DSLRs for video became more popular, Canon introduced STM (Stepping motor) lenses that provided a smoother experience; albeit at a slight disadvantage on the speed side. Nano USM addresses the ...


9

It is highly dependent on the design of each individual lens. Canon and Nikon lenses fall into two major groups regarding this: Lenses with full time manual focus. These lenses allow you to turn the focus ring at any time without fear of damaging the focus motor. The design of the lens allows the mechanism between the focus motor and the focus ring to slip, ...


8

Lenses such as the AF-S Nikkor 50mm 1:1.8 G use a type of motor to move the focus elements known as a Silent Wave Motor (SWM). The technology was first developed by Canon, who refers to it as an UltraSonic Motor (USM). It has since been adopted by many lensmakers and is known by such monikers as Supersonic Wave Drive (SWD) - Olympus, Supersonic Drive Motor (...


8

Actually, it's kind of the opposite. You need a lens with autofocusing capabilities--you just don't need one with a focus motor. That is, you'd still need AF lenses, they just don't have to be AF-S or AF-I lenses. AI lenses, for example, were designed before Nikon added autofocus to its cameras and lenses, and can only be manually focused, regardless of ...


6

The 200 f/1.8L is indeed focus-by-wire only. Taking apart the lens is not a problem, but finding replacement parts is - they're no longer available from Canon and the Canon service centres are unlikely to have any in stock. I looked at buying a 200 f/1.8L with a broken AF system, the seller had found someone selling the replacement USM unit but even then I ...


6

A focus motor without autofocus can be useful for manual remote control of the focus. For your particular example, the Rokinon 24mm, I think that the information on the Lenshero webpage is simply wrong.


6

You are comparing two lenses in different price ranges. Some of the price difference naturally comes from the focus motor, but most of it comes from the more expensive one having: Vibration Reduction (VR) More advanced optics (17 lens elements compared to 13) Extra-low Dispersion glass (ED) Internal Focusing (IF) There are certainly cheaper lenses with ...


6

You can use a polarising filter on any lens. However, using a "directional" filter like a polarising filter or a graduated neutral density filter on a lens where the front element rotates when it focuses is a bit of a pain: you get the scene lined up, rotate the filter so that it's where you want it, focus... and then the filter rotates, so you have to ...


5

The problem with putting something between the lens and the camera is that you've moved the lens farther away from the sensor than it was designed to be. If your attachment doesn't have any optics in it, you've basically added an extension tube, and the lens will only be able to focus at close distances (possibly very close distances, like macro photography)....


5

Nikon lenses with integrated autofocus motor doesn't have the old AF connection, so they'll only focus using their internal motors. Unlike the AF-S and AF-I lenses which have an integrated AF motor, the older AF lenses have a screw connection which will be coupled with a screwdriver on the camera's lens mount. Photo: Shun Cheung


5

No. All Canon EF lenses have in-lens motors. There is no need for an in-body AF motor. The Canon EF mount is designed to have no mechanical coupling of any kind—no aperture levers, "screw-drive" AF couplers, or any other mechanical linkage between the lens and body. It is entirely electronic; all EF lenses have autofocus motors and electromagnetic ...


5

Are there any entry level DSLRs with a built in autofocus motor? Both the D3300 and the Rebel T5 don't. None of the Canon EOS cameras, right up to the top-of-the-line 1Dx, have autofocus motors in the body because every Canon EF lens has an autofocus motor of its own. So don't worry about the Rebel T5 not having a motor in the body -- if there were one, it ...


5

Possible reasons why the AF on your EF 70-200mm f/2.8 L IS II lens isn't working: The AF/MF switch is set to MF (manual focus). You are attempting to focus an object at a distance from the camera, as measured from the focal plane mark on the camera body, that is less than the MFD (minimum focus distance) of the lens or is less than the distance limited by ...


4

If I am correct, the Nikkor 70-300mm f/4-5.6G AF does NOT have an internal focus motor, unlike my old D70's kit 18-70 AF-S lens which does (I am assuming this is the 18-70 you have) Therefore I THINK the problem is that your camera body's internal focus drive motor is at fault (the little bit that sticks out from the mount-ring that looks like the end of a ...


4

Yes, different lenses can definitely have different focus speeds. When focusing, a specific group of elements are typically moved. The size and weight of a group of elements varies with a given lens formula. When focusing a small prime with only a few elements/groups, the AF motor isn't going to have to move much weight. Zoom lenses almost always have more ...


4

No — an autofocus motor in the body will not make older, manual focus lenses into autofocus lenses. Any autofocus lens needs a motor — it's what does the "auto", after all. (Just like an automobile would be just a ... moble without one.) There are two primary places where this motor can be placed — either in the lens itself, or in the camera body. Each of ...


4

You can manually focus most, but not all, Canon USM lenses without any power supplied from the camera. In fact, you can manually focus them when they're not even attached to a camera. The EF-S 17-55mm f/2.8 is one such lense that allows the focus ring to move the focus elements via a mechanical connection that is not dependent upon power and other data ...


4

There is a small black slider on the side opposite the camera grip. It has 3 positions. If you slide it to the bottom it will be in AF-S mode which stops focusing as soon as autofocus locks after you press the shutter-release halfway. It is hard to see but that is number 20 in the diagram below: It sounds like your camera has the switch in the middle which ...


3

The 18-55 STM uses the virtually silent Lead-Screw Type STM. You will not hear it auto focus. There are two types of STM auto focus: The 24mm STM, 40mm STM, and 50mm STM all use the Gear-Type STM which is not all that silent or fast. All the other EF-S STM lenses use Lead-Screw Type STM which is virtually silent and also very fast.


3

To add to TFuto's answer, it also depends on whether the camera/lens uses a digital focus ring, which isn't directly connected to the lens/motor. In that case the ring won't move during AF and you can't hurt anything by rotating it.


3

Focus will obviously change if you rotate the focus ring. There is no exception to that. Now, some lenses allow manual focus override even in Auto-mode, in Nikon world these are indicated with A-M (Auto with Manual override) on the lens. If your lens mechanics do not support this, you are working against the focus motor when you change focus manually in AF ...


3

No, you can't control which motor is used. If it's an AF-S or AF-I lens (with the motor in the lens), then the body motor isn't used and there is simply no connection between the lens and AF motor in the body. Older lenses (AF-D and AF) have no AF motor in the lens and rely on the body's focus motor. Omne's photo shows an older lens with the screwdriver AF ...


3

Canon introduced STM autofocus lenses primarily to resolve an issue that their previous Ultrasonic motors could not: smooth autofocus when shooting video. In still photography, focus occurs before the image is shot, so that how the motor gets to focus is not as big a concern. But in video, focus (well specifically autofocus) occurs while video is being ...


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