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View Full Version : Broken AF motor....?



bklassen
01-18-2006, 12:06 PM
Ok, so I've had my D50 and the Nikor 18-55 kit lens for a few months now, although I haven't nearly gotten the use of it that I would have liked, mainly due to school, busy schedule, etc. (and yes, priorities has something to do with that :o ). So anyways, I recently realized that something was wrong with my lens in AF mode. I would press the shutter halfway down to pre-focus before taking the shot, and in the viewfinder the square would turn red, yet I wouldn't hear any beep, and it wouldn't seem to focus! I thought to myself, "oh great, somethings wrong with my camera..." I took a few shots, sure enough, the pictures were not in focus. Now, I bought the camera and lens used, but unfortunately I don't recall if it was like this when I received it, or if it is a result of something I have done (I recall one time, right after getting the camear, accidentally trying to manual focus with the ring when the body and lens were both switched to AF :( ... I hear this can ruin the lens - could this be what caused the focus motor to malfunction?).

So anyways, I'm pretty much wondering if I should be talking to the guy who sold me the camera (although I'm not sure if it's because of something I have done...and it HAS been a few months since I bought it off him), or if I should be looking at getting the lens repaired? If it's too costly, is it even worth getting the lens fixed? I am hoping to pick up the new Nikon 18-200 VR sometime in the near future (want a good companion for travelling Europe :) ), so that may offset any decision to get my 18-55 repaired... Any help or opinions on this would be appreciated, thanks!

coldrain
01-18-2006, 12:10 PM
Are you sure nothing is set to MF? I understand you have to put the body and the lens to AF (and then there is something in the menu... confusing stuff).

erichlund
01-18-2006, 01:30 PM
The 18-55 is an AF-S lens. You cannot break it by manually focusing when set to AF. It is DESIGNED to work that way. That does not mean your lens or camera is not broken. You should also check that BOTH switches are in AF and not M. The lens will not auto focus if EITHER switch is on M. If this does not solve the problem, get ye to a camera store, get another of the same lens on the camera and see if it auto focuses. If not, then you should suspect the camera. If so, then suspect your lens (more likely, IMO).

Since you bought the camera used (even unused by not Nikon Auth Dlr), I do not believe you have a warranty, so if it does need repair, it's on your green. If the problem is isolated to the lens, you could always consider upgrading to a better lens, such as the 18-70 or Sigma 18-125, but that's your choice.

Don't worry too much about the AF modes in the menu system. That's AF-C and AF-S. Those are both still auto focus modes, and you seem to be indicating that the lens is not focusing at all. Now, if AF-C is set, and it's focusing, but not well, then your only problem is bad technique. Then, you need to read the manual and understand the difference between AF-C and AF-S. For a beginner, I would select AF-S, as the shutter will not release until focus is locked. When you start to shoot moving objects, then you will need to understand AF-C better, where the lens will continually focus until you release the shutter, focused or not.

K1W1
01-18-2006, 02:35 PM
My suspicion is that you have AF-C mode selected.
In AF-C you get no "beep" when the focus locks AND you can shoot without the focus being locked as has been advised in the previous post.

sherlock
01-18-2006, 04:06 PM
[QUOTE=erichlund]The 18-55 is an AF-S lens. You cannot break it by manually focusing when set to AF. It is DESIGNED to work that way.[QUOTE]

Maybe all other AF-S lenses (excluding its brother the 55-200mm) work that way, but you can not override focus manually on the 18-55 without switching to manual focus. Just thought I'd clear that up...

erichlund
01-19-2006, 01:17 AM
[QUOTE=erichlund]The 18-55 is an AF-S lens. You cannot break it by manually focusing when set to AF. It is DESIGNED to work that way.[QUOTE]

Maybe all other AF-S lenses (excluding its brother the 55-200mm) work that way, but you can not override focus manually on the 18-55 without switching to manual focus. Just thought I'd clear that up...
Really... That's supposed to be one of the big selling points of AF-S lenses. Guess you live and learn. It wasn't on my list of lenses to buy, but it's definitely on my list of lenses to stay away from now.

K1W1
01-19-2006, 02:46 AM
The bit about accidentally trying to manual focus in the OP seemed a strange to me as well. When the A/M switch is in A the focus ring does not move (more than about 1mm in each direction). If bklassen moved it more that that he must be either on the weightlifting team or have been using vicegrips. In either case then I'm sure the focus mechanism would be screwed up.
I was just assuming he meant that he gave it a bit of a wobble.

Balrog
01-19-2006, 06:47 AM
Apparently there's "Real AF-S" which has full-time manual focus, and then there's "AF-S Lite" which has the silent motor but it doesn't have the FTM capability .. the Lite version is only in the low-end consumer lenses..
Here's what Ken Rockwell says about it on his review of the 18-55

It's only half an AF-S lens. Real $1,000 AF-S lenses like the 17 - 55 AF-S have big AF-S motors wrapped around the optics and drive the focus directly. Real AF-S lenses allow instant manual focus override. This cheepie has a dinky motor driving the lens through a shaft and gears exactly as if Nikon just used the AF motor already built into the camera. It would be a better lens if Nikon skipped the AF-S motor and used those costs better elsewhere. About the only thing AF-S does is let Nikon pimp the lens with gold "AF-S" letters so camera stores can try to pitch it as a "pro" feature against the similar Canon, Sigma or Quantaray lenses. On this 18 - 55 all AF-S means is that it focuses very quietly.

As I understand it, Canon has a similar deal, with "Ring-type" and "non-Ring-type" USM lenses (the former allowing FTM, latter not...)