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-   -   Re: Photo Opportunity (http://www.velocityreviews.com/forums/t953159-re-photo-opportunity.html)

Wolfgang Weisselberg 10-07-2012 01:42 PM

Re: Photo Opportunity
 
Eric Stevens <eric.stevens@sum.co.nz> wrote:
> On Mon, 1 Oct 2012 08:18:22 -0700, Savageduck


>>For aerial work I always shoot AF-C and with tracking on because I end
>>up with the target in all sort of places in the frame, especially when
>>they are flying at a high speed. So for the TigerMoth, while it is
>>better than the Mossie single shot, the formation shot and the Anson,
>>it still seems a bit "OOF soft".


> I've complained about this lens before. My first complaints arose
> after a series of shots from a solid Manfrotto tripod. On Sun, 02 Sep
> 2012 13:25:14 +1200 in Message-ID:
> <mfc5485mmk1p1sptpoh8e293d21slsv5qe@4ax.com> I wrote:


> "I've forked over even more good money for the AF-S NIKKOR 70-200mm
> f/2.8G ED VR which lens has a very good reputation. Nevertheless I
> am not nearly as happy with the results of this lens as I am with
> the 16-85. Comparitively it lacks both sharpness and contrast. I've
> had it checked over by the local Nikon repair centre and they say
> it is performing to spec. On my limited experience the 16-85 is an
> exceptional lens."


> Since Saturday's effort I have made arrangements to take the camera
> and lens back to the service centre to try and get to the bottom of
> the problem. If necessary, they will send the lens back to the
> factory.


I assume you have tried tripod, no VR, live view AF and live view
manual focussing and lots of focus bracketing.
And that the problem doesn't clear up with stopping down.

-Wolfgang

Wolfgang Weisselberg 10-17-2012 12:34 PM

Re: Photo Opportunity
 
Eric Stevens <eric.stevens@sum.co.nz> wrote:
> On Sun, 7 Oct 2012 15:42:22 +0200, Wolfgang Weisselberg
> <ozcvgtt02@sneakemail.com> wrote:


>>Eric Stevens <eric.stevens@sum.co.nz> wrote:
>>> On Mon, 1 Oct 2012 08:18:22 -0700, Savageduck


>>>>For aerial work I always shoot AF-C and with tracking on because I end
>>>>up with the target in all sort of places in the frame, especially when
>>>>they are flying at a high speed. So for the TigerMoth, while it is
>>>>better than the Mossie single shot, the formation shot and the Anson,
>>>>it still seems a bit "OOF soft".


>>> I've complained about this lens before. My first complaints arose
>>> after a series of shots from a solid Manfrotto tripod. On Sun, 02 Sep
>>> 2012 13:25:14 +1200 in Message-ID:
>>> <mfc5485mmk1p1sptpoh8e293d21slsv5qe@4ax.com> I wrote:


>>> "I've forked over even more good money for the AF-S NIKKOR 70-200mm
>>> f/2.8G ED VR which lens has a very good reputation. Nevertheless I
>>> am not nearly as happy with the results of this lens as I am with
>>> the 16-85. Comparitively it lacks both sharpness and contrast. I've
>>> had it checked over by the local Nikon repair centre and they say
>>> it is performing to spec. On my limited experience the 16-85 is an
>>> exceptional lens."


>>> Since Saturday's effort I have made arrangements to take the camera
>>> and lens back to the service centre to try and get to the bottom of
>>> the problem. If necessary, they will send the lens back to the
>>> factory.


>>I assume you have tried tripod,


> Yes


>>no VR,


> Yes


>>live view AF and live view manual focussing


> I don't trust live view manual focussing. The screen isn't as sharp as
> the viewfinder.


The screen shows what comes of the sensor and the viewfinder can
be misaligned in respect to the lightpath to the sensor.

>>and lots of focus bracketing.


> Not that but I do know how the lens focusses and have no qualms about
> relying on either the view finder or the AF.


View finder: see above.
AF: unless you use live view AF, same problem as the view finder.

>>And that the problem doesn't clear up with stopping down.


> Not really.


> I've just heard back from the repair centre and (for the second time)
> they say the lens is performing as expected. They have also confirmed
> that it is not the camera. They did suggest that I would have been
> better off using 9-point autofocus rather than the single.


Back to focusbracketing.
And trying and trying.

-Wolfgang

Wolfgang Weisselberg 10-20-2012 11:06 AM

Re: Photo Opportunity
 
Eric Stevens <eric.stevens@sum.co.nz> wrote:
> On Wed, 17 Oct 2012 14:34:33 +0200, Wolfgang Weisselberg
>>Eric Stevens <eric.stevens@sum.co.nz> wrote:
>>> On Sun, 7 Oct 2012 15:42:22 +0200, Wolfgang Weisselberg
>>>>Eric Stevens <eric.stevens@sum.co.nz> wrote:


[AF-S NIKKOR 70-200mm f/2.8G ED VR: lowish sharpness &
contrast]

>>>>I assume you have tried tripod,


>>> Yes


>>>>no VR,


>>> Yes


>>>>live view AF and live view manual focussing


>>> I don't trust live view manual focussing. The screen isn't as sharp as
>>> the viewfinder.


>>The screen shows what comes of the sensor and the viewfinder can
>>be misaligned in respect to the lightpath to the sensor.


> It doesn't show what comes of the sensor.


It does. :-)
Where else would it get it's data from?

> The resolution of the sensor
> is much better than the screen. You can enlarge a critical area of the
> image in the screen to check on focus when the camera is being used on
> a tripod but you are still not seeing the image as it comes off the
> sensor.


OK, if your camera is not showing a live view magnification
usable for critical AF for static objects ...

But in the end it does not matter. Live view AF delivers as close
and as good a group as manual focussing, i.e. it's repeatable
and good.


>>>>and lots of focus bracketing.


>>> Not that but I do know how the lens focusses and have no qualms about
>>> relying on either the view finder or the AF.


>>View finder: see above.
>>AF: unless you use live view AF, same problem as the view finder.


> Are you still discussing focussing via the screen?


I am discussing that both the view finder and PDAF can be
misaligned in respect to the sensor and therefore are useless
to test if a lens copy is bad, or not well matched to the body
or merely not well matched to viewfinder and PDAF. The last one
can be ameliorated to some degree with microAF-adjustments.

>>>>And that the problem doesn't clear up with stopping down.


>>> Not really.


>>> I've just heard back from the repair centre and (for the second time)
>>> they say the lens is performing as expected. They have also confirmed
>>> that it is not the camera. They did suggest that I would have been
>>> better off using 9-point autofocus rather than the single.


>>Back to focusbracketing.
>>And trying and trying.


> I'm all ready to carry out some more tests, as soon as the gale eases
> and it stops raining. Unfortunately the weather has been foul for the
> last two weeks and shows no sign of improving.


OK, so which distance to object are you testing? The repair
center only has this big room as a distance, if you shoot your
distant mountains/bell towers/... you a) have all that turbulent
air and haze in the way and b) are testing close to/at infinity,
which the test center cannot.

-Wolfgang


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