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Heads together please guys...

Steen

Senior Subscriber Member

Fully understood, emr :thumbup:

My 'nitpicky' designation (quoted by Tim) was in no way aimed at your comment, only at the Nikon service folks if they are hard to convince about something being wrong here.

I think it's pretty obvious that something is not ok.
 

Jan Brittenson

Senior Subscriber Member
Looks like the plane of focus is slightly tilted, and the chromatic aberrations look like spherochromatism. Shoot a white wall wide open at infinity and see if the vignetting is symmetric around the image center. If not the lens axis is tilted.
 

D&A

Well-known member
There's no doubt there's some asymmetry going on but the source of it is hard to determine. In relationship to my previous post, if it's lens related, I have some doubts whether Nikon can fully address the solution in that particular sample. Again its a bit difficult to say.

Dave (D&A)
 
A

APH

Guest
Hello,
I wouldn't read too much into Nikon not being able to see the problem, and from the data you have it looks to me like the lens(es) being at fault. If it were the mount / sensor alignment that was off the problem would show up with other lenses. I'd suggest that you might try repeating your test focussing the problem right hand side manually with live view. If the mount / sensor were misaligned, and the lens good you should be able to get a sharp image on the right. If you can't get decent sharpness manually focussing on this side it must be the lens that is off in some way. Hope that is of some help.
 

Mr.Gale

Member
Tim, I was out and about yesterday and took these snaps. I'm not sure if they are a good comparison or test but I'll let you decide.
I tried to use the same setting as you with the exception of exposure time.

Nikon D800E with 24-120mm
Focal Length 35mm
F Number F5.6
ISO 200

On close examination the sharpness is the same on both sides. The corners are soft and there is some CA both of which, I believe, are typical of this lens.

I hope this helps,
Mr.Gale







 

tashley

Subscriber Member
Thank you everyone, especially for the above sample shots, which have me packing my balaclava and heading Saratoga! ;-)

I am back home now and reunited with the damned Nikon gear and as soon as the rain lifts I will, sigh, yawn, test it yet again and report back!
 

robsteve

Subscriber
Question is ... why can Leica deal with such issues and solve them and Nikon can't???
The Leica lenses are machined metal, while the Nikon are typically plastic. In the case of Leica they will adjust for tolerances by measuring sub assemblies and lenses for their tolerance to the design specification. In other words they test each lens and try to put the parts and elements together so the manufacturing tolerances cancel each other out.

To answer how they deal with them after the fact, the APO or ASPH lenses go back to Solms and I assume they just recheck the assemblies and if one is out of specification, replace it.
 

tashley

Subscriber Member
I said I'd report back so here goes:

Twelve days ago, I sent off both the camera and lens to a very solicitous-sounding Nikon UK service. Yesterday it arrived back and they had apparently replaced a Grip Unit and a Bottom Cover Rubber Unit, neither of which I had asked them to look at. There was no mention of the lens other than Check, Test & Clean.

The assymetrical focus behaviour is still clearly evident. So I called them today and was pretty blunt. They said they'd call back. which they did. I was told that the head of service himself had look at it, that there was no problem with it at all, that I should read the technical supplement about the D800/E and be aware that high resolution sensors are demanding of technique.

The clear implication (and I told them that I took this as the clear implication: they did not disagree) is that I am either imagining the issue or that my technique is wrong. I did point out that poor technique is unlikely to cause a lens to be blurred on one side only but hey ho.

I quote, from memory: 'The service manager is willing to give you a replacement but he says there's no point since there's nothing wrong with what you have, it is all within spec."

For anyone still interested (and frankly this is now beyond irritating and far into dull, even for me)... watch this space. As a service to mankind, and out of a slight, residual hope of eventually getting some use out of the $25,000-odd I have invested in my pro-level Nikon system, I am about to show my teeth quite aggressively... but first I am going to do a bullet proof test and show the results here, as a final sanity test for me based on the opinion of all my expert friends here.

If those who have a moment care to pass judgement and, should they agree with me that this is not within any reasonable definition of 'spec', I will pursue the matter with really quite enormous vigour and vim. It's my New Year's Resolution.
 

D&A

Well-known member
Hi Tim,

I can't begin to tell you the sheer number of both expensive and moderately priced lenses that I've encountered asymmetry issues with, not unlike your current 24-120mm. There is a limit to both the physical adjustment the manufacturers service center can perform in a given sample of a particular lens, depending on its design and what's causing the issue.

Secondarily is how much and to what length they are also willing to go, in trying. What's considered acceptable to them may not be acceptable to the end users and in your case I have no doubt to the legitimacy of your complaint. With regards to asymmetry and in cases of lenses that one would expect fairly equally performance on both sides of the frame, been there and done that, including lenses that got shipped off back to Japan.

Interestingly, it was in the very 1st generation of Nikon's 24-120mm lens, that the asymmetrey in many samples was so severe and obvious, that they instituted a formal recall for adjustment. From all I've seen and heard, it resulted in marked improvement, but not a complete success.

Initially when these lenses were shot a 24mm, from what I recall, one half of the frame was soft/blurred, while the other half was OK. Sort of split down the middle, relatively speaking. Although that lens had a different optical design than the current f4 VR version, I wonder if any of the original design is a holdover. I doubt it, but one never knows. If one of the aspherical elements resin is poured unevenly in a given sample, then it doesn't surprise me if adjustment is of limited value. Of course this is only conjecture on my part. Hope you get this all sorted out without tearing out too much of your hair.

Dave (D&A)
 

Steen

Senior Subscriber Member
Heads together please guys ...


This is really far out.

I assume you have shown them the same picture link you provided in your first post here http://tashley1.zenfolio.com/img/s8/v85/p1335847198.jpg

If they cannot see the asymmetric behavior in that picture then they are so incompetent that this case deserves to be published e.g. on your own photography blog Tim Ashley Photography | Blog

I also suggest you shown them this very forum thread http://www.getdpi.com/forum/nikon/42555-heads-together-please-guys.html

And what is the exact name of this Nikon UK service company, is it owned and run by Nikon or is it a third party company ?
 

Leigh

New member
It's probably a thermal issue. Metal and glass expand and contract with temperature.

Can you review the images and determine if it occurs in certain environments?

It's impossible for a service tech to replicate this kind of problem.

- Leigh
 

tashley

Subscriber Member
Thanks Dave - your opinion is important to me given your pedigree... I must say however, that it's not my hair I intend to tear out!

What has me riled is not that the lens (or possibly the body) has an error: I'm pragmatic, I've owned an awful lot of gear and I know what the 'hit rate' is. No, my current itch is caused by the flat refusal of the tech team to recognise that there is any problem at all and their patronising behaviour, attempting to make their fault into my fault. It is so not on.

An example: before they accept a return, they insist that sample images are provided. This time, wise to their ways, I uploaded the samples to a 'quarantined' page that would show me if anyone apart from me visited and to which only they were given the address. The page didn't receive one hit. When challenged with this, they said that their tech guys don't have access to the internet and that I should have sent a file on disc, something they omitted to mention up front and something they have never mentioned on any of my previous repairs...

Grrr!

Hi Tim,

I can't begin to tell you the sheer number of both expensive and moderately priced lenses that I've encountered asymmetry issues with, not unlike your current 24-120mm. There is a limit to both the physical adjustment the manufacturers service center can perform in a given sample of a particular lens, depending on its design and what's causing the issue.

Secondarily is how much and to what length they are also willing to go, in trying. What's considered acceptable to them may not be acceptable to the end users and in your case I have no doubt to the legitimacy of your complaint. With regards to asymmetry and in cases of lenses that one would expect fairly equally performance on both sides of the frame, been there and done that, including lenses that got shipped off back to Japan.

Interestingly, it was in the very 1st generation of Nikon's 24-120mm lens, that the asymmetrey in many samples was so severe and obvious, that they instituted a formal recall for adjustment. From all I've seen and heard, it resulted in marked improvement, but not a complete success.

Initially when these lenses were shot a 24mm, from what I recall, one half of the frame was soft/blurred, while the other half was OK. Sort of split down the middle, relatively speaking. Although that lens had a different optical design than the current f4 VR version, I wonder if any of the original design is a holdover. I doubt it, but one never knows. If one of the aspherical elements resin is poured unevenly in a given sample, then it doesn't surprise me if adjustment is of limited value. Of course this is only conjecture on my part. Hope you get this all sorted out without tearing out too much of your hair.

Dave (D&A)
 

tashley

Subscriber Member
Re: Heads together please guys ...


This is really far out.

I assume you have shown them the same picture link you provided in your first post here http://tashley1.zenfolio.com/img/s8/v85/p1335847198.jpg

If they cannot see the asymmetric behavior in that picture then they are so incompetent that this case deserves to be published e.g. on your own photography blog Tim Ashley Photography | Blog

I also suggest you shown them this very forum thread http://www.getdpi.com/forum/nikon/42555-heads-together-please-guys.html

And what is the exact name of this Nikon UK service company, is it owned and run by Nikon or is it a third party company ?
Hi Steen, thanks for your moral support!

The images I provided were different but showed the same behaviour and I think did so very clearly. In fact they were probably a better example.

The service facility is part of Nikon itself. And, when I have re-tested in the most bullet-proof way I can, I will indeed be writing about it! I don't want to use my blog to pursue vendettas or spread negative energy but I do think that this is the sort of thing that other photographers should have information on before making their purchase decisions....
 

tashley

Subscriber Member
It's probably a thermal issue. Metal and glass expand and contract with temperature.

Can you review the images and determine if it occurs in certain environments?

It's impossible for a service tech to replicate this kind of problem.

- Leigh
Hi Leigh,

It seems to happen at any temperature - and whilst I do understand that certain problems are hard to replicate in a lab, if the guy stepped outside for a moment and shot a real image, he'd find that it's pretty hard NOT to replicate it!
 

tashley

Subscriber Member
OK, I'd really appreciate it if anyone has a chance to look at these:

This shot was focus bracketed on the central Reikan chart with the aim of checking for sharpness differential on the labels of the file boxes far left and right. I chose the sharpest shot. F5.6 and I show a link to the original file and then two crops.

Full-size original of this here


Crops:




Next, and I will make no comment because I am interested to see what people think, is an image focussed on the tower, centre, using live view at the centre of the frame and then two further shots, with the camera rotated on the top of the Cube so that the tower is far left and far right of frame. Focus unchanged between the three shots. The aim of this exercise was to show what I suspected as being a very different placement of DOF, indicating differing planes of focus on each side of the lens.

This is the scene:


Full sized files of each shot for comparison are
here
and
here
and
here

I think the answer is clear but any observations people have would be much appreciated. And the $64,000 question is: if you had this result, would you feel justified in kicking up a fuss when told that there is nothing wrong at all and that the performance of the lens+body combination is 'within spec'?
 

vjbelle

Well-known member
Tim,

I read your posts and I just really feel for you but you are causing yourself way too much pain and suffering. Nikon is never going to repair that lens. If, buy chance, they would exchange it for another you might, just might, get lucky and get a better copy. My major rules are don't buy any lens from anyone who won't take it back and test immediately. Your methodology is on the money but your expectations for any kind of zoom - and some primes - are beyond what I think any of them can deliver. I've run into all of this stuff with Digitars, Leica's, Nikon's, Canon's, Hasselblad's...... all of them are a crap shoot. Test immediately and if its not up to what you want then send it back.

You gotta just stop this..... you're going to drive yourself nuts. I don't own any zooms......:thumbdown:

Victor
 

tashley

Subscriber Member
Opinion appreciated and you may well be right. I feel like pursuing it because I have seen results from lenses which are much better and also because it just p***s me off to be told by a service dude that there is 'nothing wrong with it' when there so plainly is. If manufacturers are allowed this degree of slop on a kit lens, so be it - but this lens is high-mid price, pro spec and recommended for the D800...

Also the problem with the 'return window' is that when switching systems (maybe a twice in a lifetime experience for most serious photographers but seemingly worthwhile when the earth moves as it did with the introduction of the D800) one acquires a lot of new gear in quick succession and some problems do not become evident quickly. But that really is my fault... I ordered this lens while awaiting my d800's original arrival and by the time I got the camera, the lens was already 'through the window'...
 

D&A

Well-known member
Tim,

I read your posts and I just really feel for you but you are causing yourself way too much pain and suffering. Nikon is never going to repair that lens. If, buy chance, they would exchange it for another you might, just might, get lucky and get a better copy. My major rules are don't buy any lens from anyone who won't take it back and test immediately. Your methodology is on the money but your expectations for any kind of zoom - and some primes - are beyond what I think any of them can deliver. I've run into all of this stuff with Digitars, Leica's, Nikon's, Canon's, Hasselblad's...... all of them are a crap shoot. Test immediately and if its not up to what you want then send it back.

You gotta just stop this..... you're going to drive yourself nuts. I don't own any zooms......:thumbdown:

Victor
I mostly agree with what Victor has expresed and I'm sure many of us have experienced much of the same. Assuming it's not a particular mis-shapened or distorted element, vis-a-vis the pouring and curing of the resin which is part of the process of mass produced asphericals, but a consequence of misaligment of an element or grouping, I would then suggest consideration of the following:

Many zooms in the general consumer arena, whether they be pro level or mid level, often stretch general consumer technology to near it's limit when a price point is considered. It could be due to the extrodinary speed of a new zoom relative to it's focal length range, it's relatively compact size or possibly a combination of a certain max f-stop speed of a lens vs. it's extended zoom range.

When one or these are mass manufactured, a perfect ideally adjusted sample may indeed just about make the grade in terms of what you're testing for. The majority of samples though will fall short to varying degrees. I emphasize the word "varying", as samples will run the gamut from near perfect adjustment/centering to a wide range of asymmetery. The more expensive and pro level the zoom is catagorized as, the somewhat less chance of such lesser samples..note I said "somewhat"!

Notice how pro level zooms have generally shorter focal length ranges? This way, a more precise alignment can be achieved at a greater frequency and if the lens is at a higher price point, possibly a bit more effort and time is spent achieving this.

A 24-120mm constant f4 zoom is probably near the limit of being able to achieve perfect symmetrey/alignment, especially in mass production...and thus a to find such as sample will take a lot of effort and testing.

Although no one said every sample of the Nikon 24-70 f2.8 is perfect, there are many more that closer to acceptable. A newly designed 28-70 f2.8 or 24-70 f4 would even be easier to achieve close to excellent alignment, assuming the price point was such that made it reasonable for Nikon to achieve this in most every sample. Sooner or later, technology in optics will change and then a 24-120 f4 lens with near perfect asymmetrey will seem like a piece of cake....and it will be the future 24-200 f4 that will give everyone headaches.

What to do is difficult to say. Either someone at Nikon will go to bat for you, or else it will be a matter of testing additional samples. One way or the other, I truly sympathize with your fustration Tim.

Dave (D&A)
 
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Alon

Not Available
Once upon a time, there was some ancient Arri cameras with something called celluloid film.

At that time, I was a kiddo and could not understand why there was one guy on the crew with a long tape measure and he was called the focus puller.

Fast forward and what has it got to do with Tim predicament?

I am wondering if we are not at the same old problem where the plane of focus is not in perfect parallel and equidistant with the scene.

In other words, although to the eye both plants pots seem to be equidistant to the camera position and plane of focus but probably they are not.

A minute "angled" movement on such camera will "amplify" the focussing difference between extremes and will not render the same focussing for each side.

The solution, buy a tape measure and make sure the camera is at equidistant lenght from both extremes....only joking...a laser measuring thingy will do :D

I appreciate this might sound un-digital but we have been there and got the T-shirt....maybe, just maybe you are facing a similar situation.

On a comparative note. Suppose you are testing the camera on a flat wall with some measuring lines and circles of some kind. The camera should be in the perfect middle of the target and both sides of the target should be at the same distance from the camera focus. The camera and target should be in perfect parallel and frankly this is more easily said than done.

Tim, give it a thought!
 
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