Screw Drive Torque

I wasn't really sure where to put this thread but thought maybe the lens area was the best.

I currently own a Nikon D7000 that I use with an 80-200 F2.8 push pull. With AF-fine tune, I have got it to focus but it can sometimes be a bit slow refocusing when tracking. Thats not a huge deal at the moment but if I were to buy a new camera, I would like to know the lens motor has more torque. I can't see this rated anywhere - does anyone know if such a resource exists?

kierenlon said:

I wasn't really sure where to put this thread but thought maybe the lens area was the best.
I currently own a Nikon D7000 that I use with an 80-200 F2.8 push pull. With AF-fine tune, I have got it to focus but it can sometimes be a bit slow refocusing when tracking. Thats not a huge deal at the moment but if I were to buy a new camera, I would like to know the lens motor has more torque. I can't see this rated anywhere - does anyone know if such a resource exists?

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Very interesting question, I don't recall that it has been asked before. I doubt if Nikon has put info out to public. I think you have the correct forum & should have some interesting answers. If you want faster then a solution is AFS lens, Yes More $.

The only comments I have ever read regarding this issue were in one of Thom Hogan's columns. He commented in passing that the motors in the pro bodies were stronger than the motors in the consumer bodies.

If pressed, I would probably expect the newer bodies to have better motors than the older bodies simply because one might expect the development of the electrical components to move in that direction, but that's just a WAG.

In your specific case, the newer bodies tend to have further developments in AF functioning anyway, so that may help also.

Keep In mind that the screwdriver autofocus is a slow design. One might even say a poor design. Even the best bodies will produce slow autofocus. I don't know what kind of improvement you can expect going to a newer body with the screwdriver. Just know that it will be slower than a new lens. Isn't this the same reason pros went with Cannon back in the day?

I don't "think" a new camera would have less torque.

Sooo, this is actually not true. But it is in away, now.. Since its 15+ years since a body with a motor that could compete with the AFS design was produced.

The old F5 and the first (real) Nikon DSLR D1 and later D1h/D1x had a faster motor than any of the newer bodies.. Or maybe it just had more battery power to power it, I don't know. This changed with the D2h, and I guess it was because they went along with a different battery system, but that's my guess.

The F5/D1 series could focus most AF-D lenses faster than it could focus the early AF-S lenses, only advantage at the time was silence focus.. But since improvements are made all the time im sure the newest generation of AF-S, the E series lenses are taking the speed crown.

For example. The 50mm 1.8 and 1.4 AF-D are still on today's bodies faster focusing than the AF-S version

To the OP, yes there are difference in the AF force of the screw driver system used in different cameras, I don't expect it to get any better with years. there might still be a difference between Consumer and Pro bodies.

So, outside of 2 obsolete camera bodies, screwdriver autofocus is slow, even compared to first generation motor driven lenses. I agree that Nikon won't invest much time or money into this motor, or software, in new cameras, but I also don't think they would cripple it.

Usually with any moving parts, they tend to get harder to turn with age. Does that happen with these lenses? Does the autofocus screw spin freely like when they were new? Does the moving parts in the lens gum up a little and become harder to move?

Is it possible that a different 80-200 would autofocus faster than your lens because of this? Would that make more of a difference than a newer body?

Brian From WI said:

So, outside of 2 obsolete camera bodies, screwdriver autofocus is slow, even compared to first generation motor driven lenses.

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I'm not seeing this in use. For example I was using a 85mm f1.8G on a D700 and when I switched to a 85mm f1.4D, I didn't notice any appreciable change in the AF speed, if anything the old D lens seemed faster and more accurate. I've shot pictures of my dog running full bore straight at me with a 80-200 2 ring and it had no problems tracking it reliably.

Brian From WI said:

Usually with any moving parts, they tend to get harder to turn with age. Does that happen with these lenses? Does the autofocus screw spin freely like when they were new? Does the moving parts in the lens gum up a little and become harder to move?

Click to expand...

Actually almost any mechanical device gets easier to turn with age as they "break in" (the parts mate themselves to each other) unless the lubricant breaks down into a gummy mess, which would mean they need a CLA. I'm not sure what moving parts you are referring to that behave in the opposite fashion? I've never see anything that did, unless there was a lubricant failure that caused the parts to become damaged..

--
Stacey

Wow - a lot of responses while I was away. I thought it might have been something measured as every other camera metric I can think of seems to have been covered online.

I suppose a little background on the OP, I'm a hobby shooter and have found (for me at least) a Nikon system the lowest cost to value system I can get. If I factor in body and lenses, at least the ones I am looking come in much cheaper in total that (excluding perhaps canon) the other brands. I picked up the 80-200 last year from a Japanese ebay seller for £250 and can't believe the excellent condition it is in. I have no intention of trading up to newer or more expensive glass as I'm a hobby shooter, so no money comes back from my camera spends.

I remember back when I bought my D7000 reading forum comments saying the D300 had more torque. I used to own a D70s that I regret selling, it would be interesting to know how it stacks up against the D7000, D300, D750, D500 etc. As I mentioned, not a big deal either way but a curiosity I would like to know.

I found an old (2012) thread. Maybe not that much in it after all:

Brian From WI said:

So, outside of 2 obsolete camera bodies, screwdriver autofocus is slow, even compared to first generation motor driven lenses. I agree that Nikon won't invest much time or money into this motor, or software, in new cameras, but I also don't think they would cripple it.

Usually with any moving parts, they tend to get harder to turn with age. Does that happen with these lenses? Does the autofocus screw spin freely like when they were new? Does the moving parts in the lens gum up a little and become harder to move?

Is it possible that a different 80-200 would autofocus faster than your lens because of this? Would that make more of a difference than a newer body?

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Eh ! where did you get this information ? Its simply wrong lol

Not only is screw drive not slow at all but its actually faster than most of the new lenses. A lot of the time it can be down to things like, if the lens has a long or short focus throw. A lens that will focus in a half turn will focus twice as fast as a lens that needs a full turn ect.

If anything the exact opposite is true. Most G lenses are slow compared to the D lenses. Lenses like the 24-70 G are certainly faster, but the D series screw drive lenses are far from being slow. There are slow and fast to focus individual lenses in both camps. For example, there are two versions of the 70-210 F4-5.6, this one then the later D version. The D simply designates the lens transfers distance information to the camera for better more reliable flash exposures. At the same time, even though the optics are the same, Nikon also made the focus path half as short, thus almost doubling the focus speed.

This is a method used by all lens makers, even with the G lenses. A very short focus throw can be really hard to focus manually, as even a very slight turn can make a huge difference. So all lens manufacturers decide upon where they think the best balance lies.

too old for this said:

The only comments I have ever read regarding this issue were in one of Thom Hogan's columns. He commented in passing that the motors in the pro bodies were stronger than the motors in the consumer bodies.

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This is definitely true in my experience.

too old for this said:

If pressed, I would probably expect the newer bodies to have better motors than the older bodies simply because one might expect the development of the electrical components to move in that direction, but that's just a WAG.

Click to expand...

That's not necessarily the case.

too old for this said:

In your specific case, the newer bodies tend to have further developments in AF functioning anyway, so that may help also.

Click to expand...

I can tell you for example that the screw drive motor in the Df and D600/610 are identical. It's an intrinsic part of their AF design. The motor in these cameras are "squeely" too, making a lot of higher pitched noise. The D800 & D810 have quieter and stronger motors, as does the D500. The D4/5 series also have better quality motors in. I know this because the noise bothered me on my AF-D lenses with my Df and I asked Nikon for information on whether it was an issue or 'feature'. It was the latter, something I've also confirmed for myself (I asked about oiling the mechanism). I then asked Nikon for information on other bodies and also tried AF-D lenses on different bodies - there is quite a variation between the consumer models and lower end FX models and the higher end Pro bodies. I never got consistent accuracy with AF-D lenses on my Df, one of the reasons why I reluctantly sold it. My D500 by comparison is awesome in this department.

Thanks for the info on the d500. Good to know it's not taking a step in the wrong direction.

russbarnes said:

russbarnes said:

If pressed, I would probably expect the newer bodies to have better motors than the older bodies simply because one might expect the development of the electrical components to move in that direction, but that's just a WAG.

Click to expand...

That's not necessarily the case.

Click to expand...

I have no personal experience in this area, so Just as a matter of idle curiosity and for future reference, which newer bodies have you identified with weaker motors than a comparable older body ? Talking digital here, not film.

Stacey_K said:

Brian From WI said:

So, outside of 2 obsolete camera bodies, screwdriver autofocus is slow, even compared to first generation motor driven lenses.

Click to expand...

I'm not seeing this in use. For example I was using a 85mm f1.8G on a D700 and when I switched to a 85mm f1.4D, I didn't notice any appreciable change in the AF speed, if anything the old D lens seemed faster and more accurate. I've shot pictures of my dog running full bore straight at me with a 80-200 2 ring and it had no problems tracking it reliably.

Stacey_K said:

Usually with any moving parts, they tend to get harder to turn with age. Does that happen with these lenses? Does the autofocus screw spin freely like when they were new? Does the moving parts in the lens gum up a little and become harder to move?

Click to expand...

Actually almost any mechanical device gets easier to turn with age as they "break in" (the parts mate themselves to each other) unless the lubricant breaks down into a gummy mess, which would mean they need a CLA. I'm not sure what moving parts you are referring to that behave in the opposite fashion? I've never see anything that did, unless there was a lubricant failure that caused the parts to become damaged..

--
Stacey

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Love the pic. Would just re-iterate that I use the 80-200mm on a D700 for around 6 different indoor and outdoor sports and a number of events; it's very quick to focus. Works well on a D7100 too, but I think quicker on the 700 - as mentioned Thom has discussed the motor speed of the pro bodies, also Rockwell and I think Joe McNally and Dave Black.

too old for this said:

russbarnes said:

too old for this said:

If pressed, I would probably expect the newer bodies to have better motors than the older bodies simply because one might expect the development of the electrical components to move in that direction, but that's just a WAG.

Click to expand...

That's not necessarily the case.

Click to expand...

I have no personal experience in this area, so Just as a matter of idle curiosity and for future reference, which newer bodies have you identified with weaker motors than a comparable older body ? Talking digital here, not film.

Click to expand...

I am no oracle on the subject believe me, but as I said in the last post, the D600, D610 and Df all have exactly the same motor for example. This just demonstrates the point that despite the 'development' of the camera model that the screw drive motor is not exactly the first thing which Nikon care too much about. Obviously they are no longer manufacturing AF-D lenses so at some point they are likely to drop the screw drive motor altogether rather than develop it.

russbarnes said:

too old for this said:

russbarnes said:

russbarnes said:

If pressed, I would probably expect the newer bodies to have better motors than the older bodies simply because one might expect the development of the electrical components to move in that direction, but that's just a WAG.

Click to expand...

That's not necessarily the case.

Click to expand...

I have no personal experience in this area, so Just as a matter of idle curiosity and for future reference, which newer bodies have you identified with weaker motors than a comparable older body ? Talking digital here, not film.

Click to expand...

I am no oracle on the subject believe me, but as I said in the last post, the D600, D610 and Df all have exactly the same motor for example. This just demonstrates the point that despite the 'development' of the camera model that the screw drive motor is not exactly the first thing which Nikon care too much about. Obviously they are no longer manufacturing AF-D lenses so at some point they are likely to drop the screw drive motor altogether rather than develop it.

Click to expand...

Ah. Thanx.

You can compare the D7100, D600, D800 and D4 focus motors on this site which has detailed enlargeable photos of all the components:

http://www.fixyourcamera.org/nikon-d4

maico said:

You can compare the D7100, D600, D800 and D4 focus motors on this site which has detailed enlargeable photos of all the components:

http://www.fixyourcamera.org/nikon-d4

Click to expand...

Having owned or used all of the cameras above, I can tell no difference with screw drive lenses.

scokill said:

maico said:

You can compare the D7100, D600, D800 and D4 focus motors on this site which has detailed enlargeable photos of all the components:

http://www.fixyourcamera.org/nikon-d4

Click to expand...

Having owned or used all of the cameras above, I can tell no difference with screw drive lenses.

Click to expand...

Having said this, do you think the screw drive lenses have slower autofocus?

I've never used one but base my opinion on what people say.

If you move the coupling on the shaft drive lens mount with a screwdiver there is little mechanical friction. However, on a large lens, it's clear a large ring type electric motor has greater torque and accuracy. You can see how these piezoelectric type motors work here:

http://www.pierretoscani.com/echo_shortpres.html#shortpres11

Note: many Nikon 'silent wave' primes and consumer grade lenses do no use these ring type motors. They have micro USM motors. These are no faster than D lenses because they are not direct drive and have gear trains. They are however potentially more accurate and cheaper to produce than ring types.

I've got a humble 50mm AFS f1.8 which only cost £109 GBP new. The USM motor is quiet in operation and moves the entire optical grouping back and forward to focus in a timely but not fast manner.