D800 left focusing problem - is it going away?
/forum/topic/1154218/4

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Marshall Alsup
Registered: Apr 08, 2007
Total Posts: 79
Country: United States

JimmyChoo wrote:
From what I can see, all 4 images look almost the same. If you mixed them up I wouldn't be able to tell which is which.

If you tested correctly using a wide angle lens, then you're OK


Thanks You're making me feel better about it. When I look at the 100% view of the photograph hanging on the wall (the small one) in the versions with the left auto-focus use its more blurry (especially the 4th). Maybe I can fine tune that out? I've never used auto-focus fine tune before so I might try that.



Bruce Sawle
Registered: Sep 26, 2006
Total Posts: 4167
Country: United States

They all look the same to me. Hard to tell looks like you shot these under incandescent light which can cause focus errors. Before my camera was fixed there was a definitive difference between the left and right focus at all apertures. After the fix there is no difference.



JimmyChoo
Registered: Apr 22, 2004
Total Posts: 312
Country: Singapore

There you are, two similar opinions.
Fine tuning may be OK, just as long as they don't all look equally blurred.

How often do we look at 100% crops of our images? And from wide angle lens shots, on top of which.
I would relax if I were you. You haven't got a Nikon lemon.



ausemmao
Registered: Mar 31, 2011
Total Posts: 359
Country: United Kingdom

JimmyChoo wrote:


From what I can see, all 4 images look almost the same. If you mixed them up I wouldn't be able to tell which is which.

If you tested correctly using a wide angle lens, then you're OK


Really? They don't look the same at all to me.

Marshall, I'd run the test again as the last one might just have been a straight miss (happens occasionally). If that was the best of a few, either the body or the lens needs a check.



JimmyChoo
Registered: Apr 22, 2004
Total Posts: 312
Country: Singapore

ausemmao wrote:
JimmyChoo wrote:


From what I can see, all 4 images look almost the same. If you mixed them up I wouldn't be able to tell which is which.

If you tested correctly using a wide angle lens, then you're OK


Really? They don't look the same at all to me.

Marshall, I'd run the test again as the last one might just have been a straight miss (happens occasionally). If that was the best of a few, either the body or the lens needs a check.


Did you see that I wrote "almost"?



ausemmao
Registered: Mar 31, 2011
Total Posts: 359
Country: United Kingdom

JimmyChoo wrote:
ausemmao wrote:
JimmyChoo wrote:


From what I can see, all 4 images look almost the same. If you mixed them up I wouldn't be able to tell which is which.

If you tested correctly using a wide angle lens, then you're OK


Really? They don't look the same at all to me.

Marshall, I'd run the test again as the last one might just have been a straight miss (happens occasionally). If that was the best of a few, either the body or the lens needs a check.


Did you see that I wrote "almost"?


I didn't think they were even close. The centre and right, yes. But the two left ones were obviously off, too much off to confuse them with the other two. Which is why I asked if it was a plain focus failure. I don't see how that difference is acceptable if it's a consistent difference in performance that shouldn't be there - whether the source is the lens or the body.



JimmyChoo
Registered: Apr 22, 2004
Total Posts: 312
Country: Singapore

ausemmao wrote:
JimmyChoo wrote:
ausemmao wrote:
JimmyChoo wrote:


From what I can see, all 4 images look almost the same. If you mixed them up I wouldn't be able to tell which is which.

If you tested correctly using a wide angle lens, then you're OK


Really? They don't look the same at all to me.

Marshall, I'd run the test again as the last one might just have been a straight miss (happens occasionally). If that was the best of a few, either the body or the lens needs a check.


Did you see that I wrote "almost"?




I didn't think they were even close. The centre and right, yes. But the two left ones were obviously off, too much off to confuse them with the other two. Which is why I asked if it was a plain focus failure. I don't see how that difference is acceptable if it's a consistent difference in performance that shouldn't be there - whether the source is the lens or the body.


Having had a second look, this time of each of the "100% view", which I did not notice was available as I only viewed the "regular size" images; I do agree that No. 4 is markedly different from the rest. It could be due to miss-focus. I think test No. 4 needs to be done again, perhaps a few times to ensure the consistency of it.



Marshall Alsup
Registered: Apr 08, 2007
Total Posts: 79
Country: United States

Hey guys, thanks for the conversation about this. I will run the tests again tonight and post my results.

Although I only posted those 4 images before, I did several attempts (using the left most point) starting from both infinity and from close focus. They were all off. It seemed that starting from close focus was worse, perhaps because the focus had to travel further to reach a lock.

Oh, I didn't mention it, but I was using a Tamron 28-70 f/2.8 lens @28mm and f/2.8. That is currently my widest lens.



ct8282
Registered: Nov 25, 2011
Total Posts: 2199
Country: United Kingdom

I'm going to chime in again here. I picked up my new D800 (fourth one) from the retailer yesterday. This is from a new batch they just received from Nikon so assuming they have resolved their manufacturing problem this D800 should be focus problem free right? WRONG.

I have done extensive testing of the camera, using the star focus charts on the wall, straight bar focus charts again on the wall, focus calibration charts, and just normal photo taking around the house. I have used 24mm f1.4, 14-24 f2.8, 85 f1.4, and 70-200 f2.8.

To double check a few things I also did the same testing using the D4. What I have found has really made me question a lot of things and has been somewhat annoying to put it lightly.

Ok, so in summary this latest D800 now has a better performing left AF compared to the last D800 I had, I would say about 70 - 80% compared to the centre AF point, and a worse performing right AF, I would say about 65 - 70% compared to the centre. (The percentage rating is my personal interpretation of how good it is compared to the centre). In all tests the centre AF point is absolutely spot on and shows that none of my lenses require any AF fine tuning.

In real world tests, I.e taking photos of things around the house and outside, at the wide angles the lenses appear to be back focusing a fair bit with the outer AF points but perfect with the centre point. I question however that the photos I was taking to test the AF represented anything close to the actual photos that I and most other people would be taking anyway, but the fact of the matter is that the wide angle lenses at their maximum apertures are not achieving critical focus on the items I am attempting to focus on.

Now onto the more annoying thing. When I repeated these tests using the D4 I have found that the left AF point is particularly poor when using the wide angle lenses at large apertures. The centre and right AF points are perfect.

With both bodies the longer focal length lenses do not really show much of a problem and the 70-200 vr2 at 200mm f2.8 shows no problem at all. I'm guessing this is a combination of the longer focal lengths and larger apertures that are masking the issue.

In summary I would say my D4 has the worst left AF point of both bodies, the D800 has 2 averagely poor performing outer AF points, both have spot on centre AF points.

The feedback in forums and on the websites suggests that the problem is not very widespread and is affecting people with varying levels of severity. I think the sensitivity of the outer points, variances in lens tolerance and AF point tolerances, difference in testing technique and each users ability to test accurately is having a massive impact on the quality and trust worthiness of the reported feedback we are seeing.

For me personally I have had 4 D800's now with widely varying serial numbers and all have shown problems with the outer points to varying degrees. More annoyingly the D4 is clearly also suffering with an AF problem. The fact that the D4 has not really been questioned as much publicly leads me to believe that there are a boat load of D4's out there that also have an AF problem that their owners have not yet identified. After all, the D4 and D800 have identical AF modules so why would this fault impact D800's more? This leads me on to another important point. Does an AF problem on outer AF points at wide angles and large apertures actually impact most people's shooting? I think not hence why I believe many problematic cameras haven't been identified yet.

The question now is what on earth to do about it? The retailer is concerned about the number of D800's I have had which have all had problems and they are planning to do their own testing on the latest returned body as Nikon are currently refusing to acknowledge the problem with them. The D800 I have is only 1 day old so I can request a replacement or refund at this stage. The D4 however is 6 months old so if I want this sorted it will have to go back to Nikon service centre I guess.

What a bloody nightmare. I'm massively curious to see how other bodies fare against such rigorous and specific testing and especially bodies from other manufacturers. Have any of you dual system users tested other bodies?
And also, I'd be very interested to hear from other D4 users if you fancy doing the tests on your D4.



Bruce Sawle
Registered: Sep 26, 2006
Total Posts: 4167
Country: United States

Originally when i looked at these on my IPAD i did not see teh issues. Looking at these at 100% on a monitor definitely shows the left focus issue.



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