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D800 autofocus problem

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What happens if you try it in Liveview?
 
Hello Marc,
also poster "D800",

great workup, thank you. But did you report this to Nikon? I know it may involve sending your camera in. I believe the more reports they get, the harder it will become for them to remain silent about it.

Still waiting and hoping for my D800E...

Michael
 
Mikael Risedal said:
no, I think it is a matter of control from the factory.
Click to expand...
But why there are a lot of similar complaints about D800 AF everywhere?

Well.. it shows a good control to produce "consistency"
Mikael Risedal said:
rondhamalam said:
Marc Heijligers said:
My D800 also has auto focus problems on the left AF field. The enclosed picture shows that from the middle to the right, the AF performance is as expected and good, from the middle to the left the focus performance becomes worse the further you go to the left.



The results are pretty bad overall when using the left-field AF points:



I've summarized my finding on my blog.
http://hifivoice.wordpress.com/2012/05/05/d800-autofocus-problem/
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TOF guy said:
rondhamalam said:
With more focus points and AF system of 1D series, is 5D3 AF better than d800 ?
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There is no yes or no answer to your question.

Here we're looking at an AF sensor which is not working properly. If your question is along the lines of whether 5d3 users have experienced similar issues, ie the 5d3 was shipped to them with a defective sensor, then the answer seems to be "no" (or you would read about it in the 5d3 forum). So the 5d3 has an advantage in this regard.

Now many of the D800 work properly. So maybe your question is about comparing 5d3 and D800 (one that works. It's hard to say without having used any of the cameras. On paper the 5d3 has more sensors but does it make a difference to have a few more when the sensor already has 51 points? Probably not. Does it help that the 5d3 has the AF sensor of the new 1Dx? The D800 has the same AF sensor as the D4: they both share teh same sensor as the high end models. Except that there is a compromise in the 5d3: it is not linked to the metering sensor as it is in the 1Dx. The 5d3 does not use color information from the metering sensor to track the subject. By contrast the D800 has the same AF sensor as the high end D4, and the same link between AF sensor and metering as the D4 and Canon 1Dx. Does it make a difference, probably not unless one use the specific AF modes which take advantage of this link, but that's not the way most people use AF. Honestly I've read many posts explaining how both cameras do AF very well, and I very much doubt one is better than the other at least not in a significant way.
--
Thierry
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It reminds me when people complained about 5D2 AF, in the presence on D700 AF. The 5D2 AF was really a crap but a lot of people said it was good (they used centre point only).

At the end Canon listened to the complainer, they put 1D series "new" AF on 5D3
 
But since then Canon concentrate to create much better AF.

The same as Nikon in the past when they put large effort on improving AF and the 51 AF was developed, but then they stopped developing on AF now.... busy with megapixel
 
u007 said:
Was it repeatable? i.e. do you consistently get the wrong result?
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Problems are repeatable as written: "I’ve taken many different pictures by for instance turning the camera upside down (i.e. exchange the focus points), use different type of subjects, but unsharp pictures occur consistently when a left-field auto-focus points is chosen"
 
ne beginner said:
Is it what the left AF point is on that is OOF? And the back ground is in focus? Or is the whole frame OOF, as it appears in the full size picture you posted?
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It is what is at the left AF point what is out of focus, and because the bookshelf is a flat plan hence also all other book labels in the rest of the image are out of focus. I've added two pictures to my blog where you can see that the focus is too far away when I select the left AF point of my camera.



If you get sharp images, don't worry and enjoy your camera. The intention of my blog is to summarize and describe the AF problem as good as possible so that people can see if they are affected, not to create panic. Nikon seems to have fixes in place that have been reported. I'm just waiting to see if there is a generic FW fix, or whether I need to send the camera to a service point.
 
After a full weak of testing and almost 500 pictures to test the AF system, middle, left and right points, I observed the following on a 35G 1.4 when shot at 1.4.
  • Center AF. perfect. Much better than old D700 and D3S. Very high reliability. I would state 90% of shots are perfectly in focus similar to CDAF. NO AF Fine Tuning required.
  • Right AF points. Good. slightly less success rates. 70% shots are perfectly in focus. No AF Fine Tuning needed. This seems normal as this is not a cross type AF.
  • Left AF points. Interesting. At first I had only 30% perfectly focused images with a slight backfocus (requiring -5 in AF Fine tune). Then, I stated shooting THE SAME SCENE but with slightly better lighting conditions and changed the target to a more contrasty target, and my success rate achieved also something like 70% perfect focus with no need for any fine tuning.
What I observed is very weird. The right AF point is nearly as good as the center point despite not being a cross type AF and can snap pictures easily. Then the left AF point could only achieve the same success rate for the same scene by improving the lighting conditions a bit, and replacing the target by a more contrasty and easy target to focus on. It is like it is a lot more sensitive to lighting and contrast conditions of the scene than both the center and right AF.
 
D800 said:
I did not see the comparison of Subject Distance values from images taken with left, middle, and right focus point.
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For all besides the 2 left-most focus points the focus distance is 1.259m. For the 2 left-most focus points it is 1.496m. Assuming Pythagoras is right ;), and assuming the distance to the centre is 1.26m, you would expect the sides to be at 1.34m focus distance.

I couldn't find definitive info about the interpretation of the focus distance. Some say it is used to determine the intensity of flash, and it is not extremely accurate for that reason.

So it is hard for me to see what can be concluded from these figures, besides that the figures look a weird, and are different for the 2 left-most points, which is susceptible.
 
What happens if you try it in Liveview?
 
Thanks for validating. The subject distance error will be magnified as distance increases. Try to compare those values when shooting targets at about 3m away, and you will be surprised of the differences.
Marc Heijligers said:
D800 said:
I did not see the comparison of Subject Distance values from images taken with left, middle, and right focus point.
Click to expand...
For all besides the 2 left-most focus points the focus distance is 1.259m. For the 2 left-most focus points it is 1.496m. Assuming Pythagoras is right ;), and assuming the distance to the centre is 1.26m, you would expect the sides to be at 1.34m focus distance.

I couldn't find definitive info about the interpretation of the focus distance. Some say it is used to determine the intensity of flash, and it is not extremely accurate for that reason.

So it is hard for me to see what can be concluded from these figures, besides that the figures look a weird, and are different for the 2 left-most points, which is susceptible.
Click to expand...
 
Schrumpfgermane, we've reported this to Nikon support and they basically denied this serious AF issue. They emailed us back and told us that those out of focus images are completely in focus. Here is their reply:

"Response Edgar A. via Email 05/01/2012 06:39 PM
Hello Mr. Luu,

Thank you for attaching your sample images.

After evaluating them, we have found that they are completely in focus. As you previously mentioned, this issue was only coming up when shooting looking through the viewfinder. The live view mode and the view finder have different ways of focusing, one is based on contrast and the other one based on distance. This may be the reason why some times you get slightly different results.

We would suggest you better light conditions and/or using a tripod. Also VR would help.

Regards,"
Schrumpfgermane said:
Hello Marc,
also poster "D800",

great workup, thank you. But did you report this to Nikon? I know it may involve sending your camera in. I believe the more reports they get, the harder it will become for them to remain silent about it.

Still waiting and hoping for my D800E...

Michael
Click to expand...
 
Have you tried to put the AF mode to 3D in AF-C and switch back to AF-S and try again your left Af points in AF-S? Report back if you still have the problem after that.
 
Geoff said:
How do you know this? I haven't seen anyone do the same sort of test as the OP and present the photos with sharp focus across the focus points. People who claim their cameras are fine never post the test results.
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I've seen tack sharp pictures shot with the left most sensor. So it's not all the D800's.

--
Thierry
 
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