I suspect that their "in tolerance" bench test only has to deal with
focusing. I'm not familiar with Nykon specs but Canyon specifies that
the lens will focus to within some portion of the "depth of focus".
Depth of focus is related to depth of field but measured at the focal
plane rather than subject plane. I suspect that your lens has a problem
other than focus such as a decentered element or some other not very
nice malady. The bench test is probably measuring focus accuracy by
evaluating image contrast and saying all's OK. You're right. They
probably aren't taking a shot and evaluating it.
Chuck Norcutt
londonjames@xxxxxxxxxxx wrote:
> Thanks Jez,
> Yes, the difference is pretty obvious. I had an emperor's new clothes
> moment where I had Nikon repair telling me the lens was 'within
> tolerance' and I was holding an A4 print that looked like I'd used a
> soft focus filter. I was doubting my judgement, rational thought
> process, etc. I don't know what their bench test does, but I'm sure
> it doesn't include taking a picture and looking at it.
>
> I don't have much confidence in the repair service at this point and
> I'm probably looking at having to spend another £75 to rent a lens
> next week (again), but to their credit they have said they will take
> back the lens and strip it down again as I'm not happy. I have to
> wonder whether they would do that if they had absolute confidence in
> their tolerance specs.
>
> James
>
> On 9 Feb 2008, at 09:29, Jez Cunningham wrote:
>
>> James - I've attached a picture from last weekend (you should get
>> the attachment but the list won't) taken handheld at 1/180th ISO200
>> f2.8 at 185mm with my 80-200 non-AF-S on a D-70. I can send the
>> raw file if needed, and others.
>> I let you make the comparison...
>> br
>> jez
>>
>> ---------- Forwarded message ----------
>> From: James R <londonjames@xxxxxxxxxxx>
>> Date: Feb 8, 2008 11:17 PM
>> Subject: [OM] fuzzy as hell (OT as anything)
>> To: olympus@xxxxxxxxxx
>>
>>
>>
>> To the wise oldsters of the list, who must have hundreds of years
>> experience between them and know a thing or two about testing
>> lenses...
>>
>> Today I got back from Nikon UK repair service my 80-200 / 2.8 AF-S. I
>> took some test shots and drove straight over to their facility to
>> return it. I've been trying to get it fixed for some time (British
>> understatement; one week short of 6 months and £520) and really feel I
>> need some impartial opinion at this point. They claim their most
>> experienced technician has worked on it and that it now falls within
>> tolerance.
>>
>> Please take a look and see if you would accept it. Shots are taken
>> tripod mounted, self-timer, studio flash with duration 700th/sec,
>> shutter 200th/sec. Jpegs straight out of the camera. 100% crops. I
>> tried refocusing and took several shots, then picked the best. It's at
>> 200mm f2.8, but even so.
>>
>> http://web.mac.com/jamesroyall/OM/80-200.html
>>
>> The lens seems to have a really good rep. The crop on my page labelled
>> 'momentum' comes from this page below. It's also 200mm at 2.8.
>>
>> http://www.momentcorp.com/review/nikon80-200afs.html
>>
>> What do you think?
>> James
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>> <DSC_8265.JPG>
>
>
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