Autofocus malfunction Hello, I have a Sony A200 SLR, that when you just turn it on and it checks the autofocus function, you can hear the noise of the motor trying to move the lens about 2 secs, but then it stops, and when trying to use it in autofocus, it does not work. what could be the possible solutions for it? I appreciate your help, and i ask you, since i read a post before to a guy from Iraq having a similar problem

Turn the mode dial to the green rectangle for automatic exposure. Set the autofocus switch on the lens to AF for automatic focus.

Yes.

This lens lacks the autofocus motor, so it will only autofocus on cameras with the motor. This lens will autofocus on every Nikon digital SLR except for the D40, D40x, D60, D3000, D3100, D5000, and D5100. It will autofocus with the D1 family, D2 family, D3 family, D50, D70, D70s, D80, D90, D100, D200, D300, D300s, and D700 (I hope I haven't left any out).

Every one (assuming the camera supports autofocus in the first place, of course--old film Nikons didn't). The lens has an autofocus motor, so the camera doesn't need one.

Film Nikons supported autofocus starting with the N2000. (Actually, the F3 also had autofocus capabilities, but used a different system). All the digitals support autofocus.

If you have manual focus Minolta lenses, then they are not usable on anything other than other manual focus M35mm Minolta SLR's.

If they have the Minolta autofocus mount then they will physically fit onto any of the current range of Sony Alpha SLR's and also the discontinued Konica Minolta digital SLR's, but there will be some issues:-

• there will be a 1.5x magnification factor due to picture cropping caused by the digital image sensor being smaller than a 35mm film frame. As an example, a 70-200mm zoom lens will produce an image equivalent to that of a 105-300mm lens if mounted on a 35mm camera. Lens apertures are not affected by the 1.5 crop factor.
• Earlier Minolta AF lenses relied on the camera body providing the autofocus motor. Later Konica-Minolta and Sony models lack this motor so the lens can only be used in manual focus mode.
  
• If you have a later SSM (SuperSonic Motor) equipped lens and want to use it on an Minolta Alpha/Maxxum/Dynax 9 (different model names in different countries), the camera needs a complete additional circuit board which is no longer available.
• Later Sony Alpha SLR's have far greater electronic communication with the lenses used. Many Minolta lenses will not be compatible and as Sony don't support legacy products there is no fix.

In short, Minolta MD lenses (manual focus) can't practically be used on any modern digital cameras, and Minolta Alpha (autofocus) lenses will physically fit onto a Sony Alpha digital SLR, but will act as if magnified and may not autofocus or work at all on a Sony SLR. But there's no harm in trying.

Sorry there is no absolutely definitive answer for you, but I hope that you now understand why and that you take a moment to rate my reply.

Please check if the Autofocus-switch on your lens is set to M/A. Also check if the Autofocus on your camera is switched on. For detailed information about your cameras autofocus, please check this site: http://www.kenrockwell.com/nikon/d40/af-settings.htm

The simplest thing which might have gone wrong is that you mistakenly activated the macro function. Try taking a picture of, say, a flower from a few inches: if it's sharp, you're employing the camera's macro function and need to deactivate it.

I don't recall the DSC having a manual focus setting, but check it out. If you turned it on, you need to manually adjust the focus through the zoom control in order to get sharp pictures (or turn on autofocus, of course).

Otherwise, the auto-focusing software might be at fault. There are several autofocus settings available; try cycling them all and see if the problem is reversible.

If not, either the autofocus parameters are gone awry - I'm afraid the camera'll need servicing - or maybe a dirty lens is causing the autofocus to malfunction, in which case cleaning it would solve the problem. Frankly, it's unlikely - it would take a really cleverly positioned and greasy fingerprint to fool a modern focusing engine. But you might be lucky, and it's worth a check.

Presumably you intend to use a DSLR. The automatic nature of modes relates to exposure. Lenses autofocus assuming you have turned the autofocus switch on. Switch the autofocus off if you want to manually focus. Whichever you use will not affect the modes

Here is Nikon's specs of lens compatibility for the D40X:


Compatible Lenses*: Nikon F mount with AF coupling and AF contacts Type G or D AF Nikkor:
1) AF-S, AF-I: All functions supported;
2) Other Type G or D AF Nikkor: All functions supported except autofocus
3) PC Micro-Nikkor 85mm f/2.8D: Can only be used in mode M; all other functions supported except autofocus
4) Other AF Nikkor*â¹/AI-P Nikkor: All functions supported except autofocus and 3D Color Matrix Metering II
5) Non-CPU: Can be used in mode M, but exposure meter does not function; electronic range finder can be used if maximum aperture is f/5.6 or faster
6) IX Nikkor lenses cannot be used
*â¹ Excluding lenses for F3AF

They do not recommend 3rd party lenses, ever

"... Autofocus Lock ("AF-L"). Pressing the AF-L (Autofocus Lock) button enables the Nikon F4 to lock the focus. Simultaneous lock of AF-L and AE-L is possible. "'FREEZE FOCUS" - is another great function in the F4. It allows automatic shutter release when subject enters a pre focused distance - available with Nikon MF-23 and/or the 250 exp. MF-24 Multi-Control Back. i.e. with the shutter button fully depressed, the shutter is automatically fired when a subject comes into a preset manually focused position. This function is recommended for sports races because the racing course is usually known beforehand. It also works well in wildlife remote control photography, scientific, forensic and other technical photography. ..."