Can't seem to Autofocus-->Nikon D90 Autofocus not working

limited60 · March 12, 2010

I am a novice with a Nikon D90 and D40, with the basic kit lenses (18-55 f/3.5 - 5.6 and 55-200).

I only recently bought the D90, but have found that it is very finicky with its autofocus. Meaning: In some situations, it won't autofocus while in any shooting mode.

This has happened a few times before, in various locations and lighting situations, and I've just played it off as me being inexperienced, but this a.m. I set up on a ridge on my tripod with the 18-55 lens hoping to get some shots of the mountains being lit by the sun as it came up, and, same thing. It tried to focus once, then viewfinder just stayed blurry. Nothing I did would get it to focus.

So I brought the camera inside and tried taking a few shots in a well lit room, and there was a lot of "thinking" going on with the autofocus--in, out, and back in again before actually getting focused. I put the lens on my D40, and it was lightning fast getting focused and took the picture 100% of the time.

Can anyone explain why this might be happening here?

I know the D90 is a much smarter camera, and definately a more complex piece of hardware, but I just want to rule out photographer error before I start thinking the camera might be at fault. I have less than 200 actuations, so it really is brand new.

Thanks

Wil Davis · March 12, 2010

Auto focus is not foolproof, and there's usually a section in the manual which deals with conditions where auto focus might not work as well as expected; in the manual for my Nikon the section is titled "Getting Good Results with Autofocus".

Are you able to get good results using manual focus?

HTH -

- Wil

BTW - Welcome to DGPF!

limited60 · March 12, 2010

Seems like such an obvious solution.
When I get home, I'll check that out.

I think I may have had the focus areas (pardon my loose grasp of the lingo) set up wierd.

I was trying to get a reading from my autofocus in auto mode so I could switch to manual to do a few shots for a multi-image pano.

I had a colleague come and mess about with it and it might be a problem solved. I'll get back to the board if it continues to be a problem.

Thanks for the help, and for the welcome.

pathfinder · March 12, 2010

I shoot White Lenses ( eg: Canon ) so........

But I believe if you can get fast, snappy autofocus with a lens on a D40, and the same lens on a D90 is not getting at least as fast a performance in AF, then something is awry in Denmark, unless there was a major change in subject and lighting.

Check your AF settings on your D90, but I would wonder if it is not broken somewhere.

Maybe one of the Nikonians who hang around here can give you a more optimistic answer.

Even the best AF can be challenged in the dark with soft fuzzy subjects with low contrast, but I find it hard to believe that the D40 outperforms the D90 with the same lens, and same lighting conditions.

ziggy53 · March 12, 2010

Do check the AF module of the D90 to make sure it is clean.

limited60 · March 12, 2010

ziggy53 wrote:

Do check the AF module of the D90 to make sure it is clean.

1. Not sure what to look for....this AF module....to tell if it's clean, or not.
2. It literally is brand new. Could it get dirty with such little use?
3. What would cause the AF module to be unclean this early in its life?

Thanks

limited60 · March 12, 2010

Would the fact that the lenses are AF lenses (built in AF motors IIFC), and the D90 has an AF motor on the body make a difference....is there an override, or does the camera just kind of deal with that stuff on it's own?

zoomer · March 12, 2010

Has the D90 autofocus ever worked?

Go through the manual and make sure it is set up properly.

ziggy53 · March 12, 2010

limited60 wrote:

1. Not sure what to look for....this AF module....to tell if it's clean, or not.
2. It literally is brand new. Could it get dirty with such little use?
3. What would cause the AF module to be unclean this early in its life?

Thanks

If your camera has a "sensor clean" mode, use that to flip the mirror up. The AF sensor is at the bottom of the mirror box. You typically see a pair of rectangular openings. Look for a piece of hair or lint on or above the AF sensor. The AF sensor itself is under the rectangular mask, so you need a dental mirror or similar to actually see the sensor.

Since the camera is brand new, it's not likely to find a problem, but it's possible.

deb22 · March 16, 2010

I know nothing about cameras as things go but had the exact same problem with my rebel xt and my 1x400 stabilizer zoom and asked my dad for help. After many complicated replies his last suggestion was to take the lens off and clean with alcohol the contacts on both the camera and lens. It worked instantly to my surprise!!!! If this does not work do what Ziggy said but be careful not to break it,better yet take it in and have it done.

time2smile · March 18, 2010

It just doesn't sound right.. It should lock on fast, even with the kit lenses that are AF-S in the first place. I would consider the camera to be a fault. Take one of your lenes to a camera store and try another D90 body, it sounds like you will see a difference.
Sorry....

time2smile · March 18, 2010

limited60 wrote:

Would the fact that the lenses are AF lenses (built in AF motors IIFC), and the D90 has an AF motor on the body make a difference....is there an override, or does the camera just kind of deal with that stuff on it's own?

The electronic contacts on the lens tell the camera what its suppose to do or what AF motor to use.

Zerodog · March 22, 2010

My D90 was super fast with any of my lenses. Check your AF settings and if that doesn't fix it you might have a problem with the camera.

Can't seem to Autofocus-->Nikon D90 Autofocus not working

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