D800 Autofocus issues II

Started Jan 25, 2014 | Discussions
Art Jacks Senior Member • Posts: 2,956
Re: D800 Autofocus issues II

Being old I thought I may have made a mistake so to put my mind at rest I searched through the threads I had contributed to, on Jan 20th 2013 you started a thread expressing your concerns about the AF accuracy of the D800 and 1.4 lens, you describe in the text what I recalled but there were some examples which seem to have been removed ! unless there are two forum members with the same name ?

fPrime
fPrime Senior Member • Posts: 2,743
Re: The absence of evidence is not evidence of absence
1

Simon Garrett wrote:

fPrime wrote:

Simon Garrett wrote:

We know there was a left-focus issue with early D800s (now long-since fixed), and I'm sure any particular D800 might have a manufacturing defect (or have broken).

Left AF fixed? That's a bit assumptive given the problem continues to be reported to Amazon in units sold as late as Q4 2013. It's even more troubling because not everyone rigorously tests their camera for focus accuracy upon receipt nor do most enthusiasts have the fast primes with shallow DOF required to detect the Left AF issue. If anything, the anecdotal evidence suggests that the Left AF problem persists and is not identified by Nikon's internal QC. See just one example:

Soooo many 5 stars - Did I get a lemon?, October 14, 2013

By Nelson - See all my reviews Amazon Verified Purchase(What's this?) This review is from: Nikon D800 36.3 MP CMOS FX-Format Digital SLR Camera (Body Only) (Electronics) I'll not spend too much time on this review because most problems I got has already been extensively written in here. Since on its release the D800 had the soft focus issue, I waited until now to buy it in the hope the bug had been fixed. I got the camera on Sep 15, 2013 and on the first pictures I noticed right away the bad soft left focus. Not sure about this one, so take with a grain of salt, the liveview mode apparently accentuate the soft focus issue.

I think we'd need a bit more information before regarding this as evidence. Sounds more like he hadn't got used to the camera (he's talking about his first pictures), or even buyer's remorse. Did he come back and post after more considered and detailed analysis, I wonder?

No need to wonder, Simon, look at the ensuing dialogue for yourself on Amazon. Then look at the numerous other 1 and 2 star reviews of the D800 from 2013, most are centered around focus. It's not like the user above was the one Left AF report from last year.

Either someone has evidence of a generic focus issue with the D800, or it's reasonable to assume that there isn't any generic issue. Just as it's reasonable to assume that D800s don't spontaneously morph into candyfloss and it's reasonable to assume that using D800s doesn't give you warts. I can't prove any of these, but they're reasonable assumptions given the lack of evidence to the contrary. And I haven't read any evidence here; forgive me if I've missed it.

More assumption from flawed logic.

Flattery will get you everywhere.

Nice attempt below at digging yourself out of the hole you dug. Have I endeared myself enough now?

As Carl Sagan said... "The absence of evidence is not evidence of absence."

I agree, but that supports my point. There's lots of evidence that the D800 focuses well. There's little evidence that it doesn't. The fact that we don't have evidence that the D800 works every time (which would be impossible) isn't evidence of a problem. As you say: "The absence of evidence is not evidence of absence."

Consider this... what's been suggested by Primeshooter (as well as Ming Thein, Lloyd Chambers, and others) is that PDAF on the D800 is less accurate and consistent than the D700. As such, a single mis-focused D800 image scaled to 12MP reveals little about focus accuracy in the absence of a D700 comparator image taken under similar scientifically controlled conditions. And given that the AF consistency of the D800 is suspect, really what's required here is a repeated set of comparison images scaled to 12MP.

Well, some VSPs (Very Serious People) say they've got a kind of feeling it's suspect without any definite evidence. As you say, that's not the result of scientifically controlled tests. And to say "...given that the AF consistency of the D800 is suspect..." to use your argument that looks like "an assumption from flawed logic".

Since this involves a lot of work and time (not to mention access to both a D800 and D700) it's somewhat unreasonable to ask a DPR member to report more than the empirical evidence of their relative experience of PDAF between the two cameras. My own experience is that the D800 is fine high resolution camera suitable for studio and landscape work when restricted to being mounted on a tripod and focused with Live View CDAF. For all other applications (reportage, wedding, sports, low light, and general use) the D700 is simply a better camera IMHO.

If I understand your argument: "Clever people have suggested that there's a problem but haven't done scientific tests, and it's unreasonable to ask them to do a lot of work to prove it, so we have to assume there's a problem." Hmm... I'm not totally convinced by that argument, if you don't mind my saying.

I'm afraid we do need more than empirical evidence to justify regarding the D800 AF as suspect.

Unless, of course, we're going to regard every camera as suspect because someone somewhere has said it doesn't work properly.

My, Simon, you're very presumptive to conclude all of this reverse hyperbole from my simple argument above. Basically the only thing I said was that your original conclusion about the absence of evidence being evidence of the absence of a problem was incorrect. That's just as true now as before you responded so it's not really clear you've advanced the discussion.

My only other point to the thread at large (and specifically to counter the attempt of certain D800 fan boys to squelch public discussion simply for lack of example images) is that empirical evidence should be the only threshold to posting in a users forum. It is after all a users forum, not a peer-reviewed publication where a higher threshold would be reasonable. It'd be pretty dead in here if everyone had to present scientifically valid comparative testing before commenting on their experience.

fPrime

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fPrime
fPrime Senior Member • Posts: 2,743
Re: The absence of evidence is not evidence of absence

caspianm wrote:

fPrime wrote:

Not sure about this one, so take with a grain of salt, the liveview mode apparently accentuate the soft focus issue.

What?

Agreed, the grammar here leaves something to be desired. Just for clarity, this was the Amazon user's commentary (not mine).

I believe the only reasonable interpretation of what he's saying is that the Left AF mis-focus was detectable simply viewing the images produced with PDAF and that when compared to images produced with CDAF in Live View the mis-focus was accentuated.

fPrime

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nikonuserinfo Regular Member • Posts: 278
D800, best Nikon AF system until now...

Opinions may vary, but after nearly two years with both D800 and D800e (now exclusive D800e) and after having owned about all Nikon bodies since D1 and D1h (still have themand still use them once and a while to realize how incredible good D800 is ...), D100 over D2h (still have this one as well) , D2x, D200, D300 and D300s, D3 and D3s..., my D800e beats every other Nikon body about AF speed and AF accuracy. (I also had a Canon 5D which even could not AF on an elephant with the outer AF sensors)

To avoid that the OP would accuse me of fanboyism, I post some samples in different situations and some links with more samples of my experiences with D800 AF system on my website...

  • D800e with 85mm F1.8, at F1.8, handheld while using AF-C
    Focus area as seen in Nikon View:

A crop of the focus area of the above picture:

  • A close up with 105 AF-S VR, handhold. (I have thousands of shots like these)
    The Original scene (resized to 400px widest side)

And a 100% crop of the focus area:

  • Even with a 2x converter and my 105 AF-S, using AF-C, handhold with outer left and outer right AF sensor:

And a 100% crop of the AF area...:

  • Tracking of fast moving subjects is also working incredible well with the D800 super AF system, even with relative slow focusing lenses like the 28-300 AF-S.
    You can find many samples in this topic on my website.

I post one of the samples here:

The Original scene, resized to web size:

And a 100% crop:

Thanks for your attention and kindest regards,
Stany
http://www.nikonuser.info
My former Dpreview profiles ( For which I do not have the Original email address anymore)
Stany Buyle
Photoforfun

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caspianm Senior Member • Posts: 2,471
Re: The absence of evidence is not evidence of absence

fPrime wrote:

caspianm wrote:

fPrime wrote:

Not sure about this one, so take with a grain of salt, the liveview mode apparently accentuate the soft focus issue.

What?

Agreed, the grammar here leaves something to be desired. Just for clarity, this was the Amazon user's commentary (not mine).

I believe the only reasonable interpretation of what he's saying is that the Left AF mis-focus was detectable simply viewing the images produced with PDAF and that when compared to images produced with CDAF in Live View the mis-focus was accentuated.

fPrime

I realized it wasn't yours. If he was testing PDAF, it could not be accentuated by CDAF. CDAF is the reference. Something is amiss.

Regarding amazon reviews looking at D800E reviews show excellent numbers. But the catch is both unit have the same focusing system. Go figure.

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fPrime
fPrime Senior Member • Posts: 2,743
Re: The absence of evidence is not evidence of absence

caspianm wrote:

fPrime wrote:

caspianm wrote:

fPrime wrote:

Not sure about this one, so take with a grain of salt, the liveview mode apparently accentuate the soft focus issue.

What?

Agreed, the grammar here leaves something to be desired. Just for clarity, this was the Amazon user's commentary (not mine).

I believe the only reasonable interpretation of what he's saying is that the Left AF mis-focus was detectable simply viewing the images produced with PDAF and that when compared to images produced with CDAF in Live View the mis-focus was accentuated.

fPrime

I realized it wasn't yours. If he was testing PDAF, it could not be accentuated by CDAF. CDAF is the reference. Something is amiss.

Regarding amazon reviews looking at D800E reviews show excellent numbers. But the catch is both unit have the same focusing system. Go figure.

I hear you. How about this conspiracy theory... the source of the Left AF focus problem is caused by simple production variability in the 51 point PDAF system. The most accurately aligned modules are hand picked for the D4 first with the D800e next. The D800 is inevitably built with the least planar PDAF modules that are left over in a calculated risk that the users for these low end models will be less sensitive to any resultant focus accuracy variation. The D7100 picks up the absolute worst 51 PDAF FX modules and repurposes them into DX modules since the smaller DX image circle puts less optical stress on focus performance of the edge sensors.

Then extend the conspiracy... the reason the D600/610 and Df use the 39 point PDAF system wasn't just to cripple the feature sets of the D800 and D4 respectively. They had to use it because sufficiently "accurate" 51 point PDAF modules couldn't be produced to simultaneously support six different Nikon DSLRs including the D7100.

Before dismissing this out of hand consider that Intel sells the exact same CPU as a lower or higher performing model purely based on how tolerant it is to performing accurately under load during internal QC testing.

fPrime

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Simon Garrett Veteran Member • Posts: 6,190
Re: The absence of evidence is not evidence of absence

fPrime wrote:

(snip)

My, Simon, you're very presumptive to conclude all of this reverse hyperbole from my simple argument above. Basically the only thing I said was that your original conclusion about the absence of evidence being evidence of the absence of a problem was incorrect. That's just as true now as before you responded so it's not really clear you've advanced the discussion.

My only other point to the thread at large (and specifically to counter the attempt of certain D800 fan boys to squelch public discussion simply for lack of example images) is that empirical evidence should be the only threshold to posting in a users forum. It is after all a users forum, not a peer-reviewed publication where a higher threshold would be reasonable. It'd be pretty dead in here if everyone had to present scientifically valid comparative testing before commenting on their experience.

Apart from your comments about my presumption and your entertaining comments about digging, I perhaps agree with that, but I draw a different conclusion while using apparently the same logic.  (It was a misunderstanding to say that I was using the absence of evidence as evidence of absence, but perhaps what I said was open to misunderstanding.)

Anyone can post what they like (almost) here, and it doesn't have to be based on evidence, emprical of other. But we're also debating (in this case) whether the evidence as we each see it (whether posted or not) justifies the conclusion that "the AF consistency of the D800 is suspect". The evidence of which I'm aware doesn't come close to leading to that conclusion.

We can't take it as proven that the D800 is fault-free, nor can we with any other product.

In forming a useful judgement about whether there is credible evidence that "the AF consistency of the D800 is suspect" as you put it, one needs to balance the weight and quality of evidence for and against such a conclusion.  And clearly we'll each make our own judgement about both weight and quality in such a case.

  • On the one hand, we have evidence that the D800 is widely used, highly spoken of, and no reviews I've read make critical comment about AF (I'm sure I haven't read them all, and perhaps I've missed some such comment). I have read extensive reviews making favourable comparisons of the D800 AF with that of the D700. Examples of such favourable AF comparison I can find at this moment include Thom Hogan's guide to the D800 and the review on his site (both written well after the camera was launched, and after time for negative comments to come to light). Also the dpreview D800 review comments that the AF is slower than the D4, but otherwise makes only positive comments compared to other cameras. These are in-depth, technical reviews.
  • On the other hand, there are some comments you cite suggesting a problem. I don't place much weight on Amazon and other reivew comments. For every product there are always seriously negative comments, and the quality of criticism is often very poor. The same is true of positive comments on such reviews. I've not read comments from the photographers that you cite, but as you yourself say, they are not scientific assessments, unlike the Thom Hogan and dpreview reviews which include much more rigorous testing.

Now, which set of evidence looks more convincing to you? No need to ask, I guess, as I'm pretty sure we'll come to different conclusions!

None of this proves that there is no problem with the D800 AF, but I don't really think the evidence you cite, set against so many positive (and much more scientificly rigrorous) reviews and comments comes close to justifying the conclusion that "the AF consistency of the D800 is suspect". Just because some people criticise something doesn't justify an objective and balanced conclusion that it's suspect. This is the sort of lazy judgement hurried journalists are prone to make when they give equal weight to both sides of any argument, however preposterous. (I mean lazy judgements of journalists - not yours!)  A balanced judgement doesn't mean giving equal weight to all evidence.

I wouldn't for a moment try to censor primeshooter and others finding fault with the D800, but I think the debate needs a sense of proportion.

I'm not a "D800 fan boy [who wants] to squelch public discussion simply for lack of example images". But if people can't produce example images or other reproducable evidence, then the case for concluding that "the AF consistency of the D800 is suspect" looks a bit thin to me.

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Simon

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Nikon D800
rayman 2 Veteran Member • Posts: 3,229
most people dont know how to test af systems....
2

most people dont know how to test af systems....

plus a sytem with such a high precision made for 36mp doesnt exist..

thats why Hasselblad camers only have and use one AF Point....

and I suggest you calibrate the middle af Point and just use that most of the time...

with af hold or afs.. if possible....

you need to look at af Systems on a flat target.. otherwise you also have longtitudinal

and lateral misalignment and not just distance misalignment....

Peter

caspianm Senior Member • Posts: 2,471
Re: The absence of evidence is not evidence of absence

There are fundamental differences between a defective focus module and slower CPU.

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Photo Pete Veteran Member • Posts: 4,625
Re: D800, best Nikon AF system until now...

Stany

Great images and also representative of the AF performance of my D800 under most conditions.

My only issue with the D800 focus is that AF-C tends to micro hunt when shooting under tungsten lights (typical lounge lighting), never settling on the subject. This would typically be an eye of a head and shoulders subject. My D3S never did that.

I'm currently working on posting some test images to show this using a photograph of a portrait as the focus target (flat target). Sequential images show slight variations in focus accuracy from shot to shot, depending at what point in its continuous micro hunting the AF-C focus is stopped at to take the photo.

Have you experienced anything similar? No point in sending my camera in to Nikon if this is a limitation of the AF-C performance generally.

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Have Fun
Photo Pete

Robin Casady Forum Pro • Posts: 12,898
Re: Can someone please point me to hard evidence of D800 focus problems

coronawithlime wrote:

Fair enough.

Putting the left focus issue aside for the moment, how would one certify or dispose of the APPARANTLY observed tendency of my D800 to low light focus hunt relative to my D3x and my D700? I have nothing to offer beyond my un scientific personal observation of only one sample, which settles nothing.

Which lenses? The 105mm Micro-Nikkor is renound for hunting. My experience has been that my D700 did more hunting in low light than does my D800E.

What kind of light (warm CFL, incandescent, daylight, daylight CFL, LED)?

Also, in the interest of full disclosure, my personal shooting procedures have been adjusted to take advantage of the camera's strengths and avoid what I perceive as potential weekness, so for me this is also largely academic. I'm sold on the camera

That is the best road to success. Us old guys have to laugh at someone who is outraged that a camera wont do everything perfectly for him/her in all situations.

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Robin Casady
http://www.robincasady.com/Photo/index.html
"Get your facts first, then you can distort them as you please."
—Mark Twain

Robin Casady Forum Pro • Posts: 12,898
Re: Can someone please point me to hard evidence of D800 focus problems

Simon Garrett wrote:

I've had a browse through this thread, but I've seen nothing but personal abuse and vague comments that hint at focus issues.

Sorry if I've missed it, but has anyone posted evidence of specific focus problems, with descriptions of how to recreate those problems? I mean something with enough specific information to allow any D800 user to repeat the situation, and say with certainty "yes that problem occurs with my camera" or "no it doesn't".

We know there was a left-focus issue with early D800s (now long-since fixed), and I'm sure any particular D800 might have a manufacturing defect (or have broken).

But I've read no evidence of any generic design or manufacturing fault in D800 focusing (since the left-focus problem).

If that's wrong, please correct me. With hard evidence.

As I understand it, primeshooter's complaint is that the D800 misses focus about 60% of the time when shooting indoors at f/2.8, through f/1.4. Give it a try and see what you come up with.

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Simon Garrett Veteran Member • Posts: 6,190
Re: Can someone please point me to hard evidence of D800 focus problems

Robin Casady wrote:

Simon Garrett wrote:

I've had a browse through this thread, but I've seen nothing but personal abuse and vague comments that hint at focus issues.

Sorry if I've missed it, but has anyone posted evidence of specific focus problems, with descriptions of how to recreate those problems? I mean something with enough specific information to allow any D800 user to repeat the situation, and say with certainty "yes that problem occurs with my camera" or "no it doesn't".

We know there was a left-focus issue with early D800s (now long-since fixed), and I'm sure any particular D800 might have a manufacturing defect (or have broken).

But I've read no evidence of any generic design or manufacturing fault in D800 focusing (since the left-focus problem).

If that's wrong, please correct me. With hard evidence.

As I understand it, primeshooter's complaint is that the D800 misses focus about 60% of the time when shooting indoors at f/2.8, through f/1.4. Give it a try and see what you come up with.

I wish I could.  My primes are all older, manual focus.

I'll be interested to see if this is generally found to be the case.  It would be good to narrow down whether these are isolated cases, or perhaps problems that occur in certain specific circumstances, or something more general.  I think the latter is not so likely, or it would have come up before in reviews and testing.

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Simon

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Robin Casady Forum Pro • Posts: 12,898
Re: Can someone please point me to hard evidence of D800 focus problems

Simon Garrett wrote:

Robin Casady wrote:

Simon Garrett wrote:

I've had a browse through this thread, but I've seen nothing but personal abuse and vague comments that hint at focus issues.

Sorry if I've missed it, but has anyone posted evidence of specific focus problems, with descriptions of how to recreate those problems? I mean something with enough specific information to allow any D800 user to repeat the situation, and say with certainty "yes that problem occurs with my camera" or "no it doesn't".

We know there was a left-focus issue with early D800s (now long-since fixed), and I'm sure any particular D800 might have a manufacturing defect (or have broken).

But I've read no evidence of any generic design or manufacturing fault in D800 focusing (since the left-focus problem).

If that's wrong, please correct me. With hard evidence.

As I understand it, primeshooter's complaint is that the D800 misses focus about 60% of the time when shooting indoors at f/2.8, through f/1.4. Give it a try and see what you come up with.

I wish I could. My primes are all older, manual focus.

I'll be interested to see if this is generally found to be the case. It would be good to narrow down whether these are isolated cases, or perhaps problems that occur in certain specific circumstances, or something more general. I think the latter is not so likely, or it would have come up before in reviews and testing.

You can use the green dot with manual focus lenses.

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Robin Casady Forum Pro • Posts: 12,898
Re: D800, best Nikon AF system until now...

Photo Pete wrote:

Stany

Great images and also representative of the AF performance of my D800 under most conditions.

My only issue with the D800 focus is that AF-C tends to micro hunt when shooting under tungsten lights (typical lounge lighting), never settling on the subject. This would typically be an eye of a head and shoulders subject. My D3S never did that.

I'm currently working on posting some test images to show this using a photograph of a portrait as the focus target (flat target). Sequential images show slight variations in focus accuracy from shot to shot, depending at what point in its continuous micro hunting the AF-C focus is stopped at to take the photo.

Have you experienced anything similar? No point in sending my camera in to Nikon if this is a limitation of the AF-C performance generally.

Do you have the latest firmware installed? I was able to duplicate AF inaccuracy at f/1.4 in tungsten light with the previous firmware, but it improved with the upgrade. It also went away at f/2.8 (with the old firmware)/

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Robin Casady
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Photo Pete Veteran Member • Posts: 4,625
Re: D800, best Nikon AF system until now...

Photo Pete wrote:

Stany

Great images and also representative of the AF performance of my D800 under most conditions.

My only issue with the D800 focus is that AF-C tends to micro hunt when shooting under tungsten lights (typical lounge lighting), never settling on the subject. This would typically be an eye of a head and shoulders subject. My D3S never did that.

I'm currently working on posting some test images to show this using a photograph of a portrait as the focus target (flat target). Sequential images show slight variations in focus accuracy from shot to shot, depending at what point in its continuous micro hunting the AF-C focus is stopped at to take the photo.

Have you experienced anything similar? No point in sending my camera in to Nikon if this is a limitation of the AF-C performance generally.

Do you have the latest firmware installed? I was able to duplicate AF inaccuracy at f/1.4 in tungsten light with the previous firmware, but it improved with the upgrade. It also went away at f/2.8 (with the old firmware)/

I think I'm on the latest FW, but will check tomorrow (it's 2am in the UK and probably time for some sleep!)
--
Have Fun
Photo Pete

Photo Pete Veteran Member • Posts: 4,625
Re: Can someone please point me to hard evidence of D800 focus problems

coronawithlime wrote:

Fair enough.

Putting the left focus issue aside for the moment, how would one certify or dispose of the APPARANTLY observed tendency of my D800 to low light focus hunt relative to my D3x and my D700? I have nothing to offer beyond my un scientific personal observation of only one sample, which settles nothing.

Which lenses? The 105mm Micro-Nikkor is renound for hunting. My experience has been that my D700 did more hunting in low light than does my D800E.

What kind of light (warm CFL, incandescent, daylight, daylight CFL, LED)?

Also, in the interest of full disclosure, my personal shooting procedures have been adjusted to take advantage of the camera's strengths and avoid what I perceive as potential weekness, so for me this is also largely academic. I'm sold on the camera

That is the best road to success. Us old guys have to laugh at someone who is outraged that a camera wont do everything perfectly for him/her in all situations.

So true.... my Zenit E never had these focus problems
--
Have Fun
Photo Pete

Robin Casady Forum Pro • Posts: 12,898
Re: The absence of evidence is not evidence of absence

fPrime wrote:

caspianm wrote:

fPrime wrote:

caspianm wrote:

fPrime wrote:

Not sure about this one, so take with a grain of salt, the liveview mode apparently accentuate the soft focus issue.

What?

Agreed, the grammar here leaves something to be desired. Just for clarity, this was the Amazon user's commentary (not mine).

I believe the only reasonable interpretation of what he's saying is that the Left AF mis-focus was detectable simply viewing the images produced with PDAF and that when compared to images produced with CDAF in Live View the mis-focus was accentuated.

fPrime

I realized it wasn't yours. If he was testing PDAF, it could not be accentuated by CDAF. CDAF is the reference. Something is amiss.

Regarding amazon reviews looking at D800E reviews show excellent numbers. But the catch is both unit have the same focusing system. Go figure.

I hear you. How about this conspiracy theory... the source of the Left AF focus problem is caused by simple production variability in the 51 point PDAF system. The most accurately aligned modules are hand picked for the D4 first with the D800e next. The D800 is inevitably built with the least planar PDAF modules that are left over in a calculated risk that the users for these low end models will be less sensitive to any resultant focus accuracy variation. The D7100 picks up the absolute worst 51 PDAF FX modules and repurposes them into DX modules since the smaller DX image circle puts less optical stress on focus performance of the edge sensors.

Then extend the conspiracy... the reason the D600/610 and Df use the 39 point PDAF system wasn't just to cripple the feature sets of the D800 and D4 respectively. They had to use it because sufficiently "accurate" 51 point PDAF modules couldn't be produced to simultaneously support six different Nikon DSLRs including the D7100.

Before dismissing this out of hand consider that Intel sells the exact same CPU as a lower or higher performing model purely based on how tolerant it is to performing accurately under load during internal QC testing.

fPrime

There is software that compensates for planar irregularities in the AF module. So, I doubt your CT. Here is mine: The earthquake damaged one of the machines Nikon uses to calibrate the AF system. They thought they had it recalibrated for the D800 run, but they didn't. So, a percentage of the D800s were improperly calibrated. That is "My theory, which belongs to me, is mine."

Anne Elk

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Robin Casady
http://www.robincasady.com/Photo/index.html
"Get your facts first, then you can distort them as you please."
—Mark Twain

RichRMA Veteran Member • Posts: 4,073
I didn't know about the issue when I first saw it

Before I knew anything about a focus issue a friend, an early adopter, got a D800.  He gave it to me to play with and I noticed right off that it was focusing with a prime lens about 1" off for every 48" distance.  I figured, "It needs a fine adjustment for the lens on it."  The friend ended up changing the camera three times, finally getting one that didn't have the focus issue.  It would be nice to know if tolerance variation due to cost constraints in design are responsible for this, like in the old days when lenses were done by hand and only the most expensive could be guaranteed as consistent.

seahawk
seahawk Senior Member • Posts: 2,896
Re: Can someone please point me to hard evidence of D800 focus problems

http://www.dpreview.com/forums/post/52979795

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