Low light autofocus inconsistencies...

My camera is now calibrated, autofocus works well on all my lenses, but very often autofocus does not work well indoor, in low light conditions, or with tungsten light.
It is not that my camera does not want to lock the focus, it gives me the sound and lock confirmation, but focus is very often back, or sometimes in front.
Many people are complaining about this, not just with D7000, but with all other cameras.
What are your thoughts? Why camera gives us a lock confirmation if it can not lock autofocus at desired spot?

At times when using my D3s and 24-70mm 2.8 or 85mm1.4 it will do the same under dim lit conditions. I noticed while taking shots of someone next to the Christmas tree. Something you'll just have to get used to.

I noticed it this past week with my D7000, 24-70 and SB-800, shooting in my wife's bar. I'm using the D7K while my D600 is in the shop. I had much difficulty getting autofocus to work and had many shots with back focus issues. I don't recall having such issues with the D600 and 24-70 (or the D7000 w/17-55).Here's an example of the extreme back focus

What focus mode are you using? Do you find the problem to be consistent regardless of focus mode or number of focus points? I find the 39 point system to be OK in lower light provided you're in Single Point and work in the center. Get to the edges and it will hunt.

I have tried the same, isn't it just because of the lack of light, then the lens have a hard time finding the focus point/we easily focus the wrong place?




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It's a natural way things work i guess.-
the sensor is limited..you could try shooting with the focus light on (or whatever it's called)

Low light will burden any AF systems forever, so I'd say get snappy with MF/correcting AF. Split-prism focusing screens are sheer gold in the dark.

I discovered early on that low light negatively affected autofocus with my D7000. Your best option would be to use manual focus in such situations. The auto focus assist light is another option but it only helps with shorter distances. I actually leave it turned off all the time so it's not a distraction. Usually my low light situations are events such as school events in a gym and I find it annoying when an autofocus assist light flashes.

I shoot AF-C, 9-point and the shot pictured was matrix metered (I normally shoot center or spot). Maybe the matrix messed me up.

Well, that was a given pretty much. I was mostly referring to AF hunting too much/simply being unable to focus on what YOU want in extremely low-light situations.

I almost always shoot AF-C and spot with people...This way I seldom have focus problems...

I was thinking about selling my D7000 because of that, a lot of people are complaining on D7000 and bad autofocus, but now I see all cameras have this problem in low light.
It is very bad with 35mm f1.8 G lens, 50mm f1.8 D works better, and 18-105 is even better on this. Yes, it is f3.5-5.6 and DOF is not the same as f1.8, but there is less back focus problems in low light.

It is very hard to focus manually, and Live View is really slow. AF Fine Tuning can not be used because it is not consistent.
This is taken with 35mm yesterday with a lot of light coming from the window, as you can see everything works as it should, I can focus on the eye.

Get yourself an SB700 then you'll be ok...

OK, here you have 15 photos taken with my D7000 and 35mm f1.8 G, all with a tripod and ISO100, autofocus on the center point.













Almost every time 35m is not in focus. My camera was calibrated few days a go, all together with all my lenses, 35m, 50mm, and 18-105, and all but 35mm works well with almost 90% accuracy. This 35mm does not focus at all at desired point when light is low, or with tungsten bulb.
There is so many people on the internet with this problem, does anyone have any idea what can be the problem?

Here is the link with full resolution JPGs:

http://www.mediafire.com/download/ja2hqngzye5b0m5/JPG.zip

Something tells me you should use Matrix metering with that lens. Here's a shot I just took about half hour ago with my 35 mounted on my D40. Sharp all over.

I am almost always on matrix. I doubt that is the case here...

alfaholic said:

My camera is now calibrated, autofocus works well on all my lenses

Click to expand...

Who calibrated your camera?

Also when you took the 15 pictures with the tripod did you use a remote or pressed the shutter?

Nikon official dealer calibratedy camera.

I used timer, of course.
You can see focus point mostly behind the subject, there is no motion blure.

Then try Auto -AF and see what happens.

Nothing. Tried all AF modes, but the problem persist.