Guys
It is perfectly plausible that (on rare occasion) you may get a under
performing lens in a manufactured series. It might be that it just squeaks
by the lower quality control value after assembly, or the torque on one of
the retaining rings is inadequate to give it sufficient resistance to de
centering associated with shocks. It subsequently becomes de centered in
shipment or handling.
By way of anecdote.......Out of 20 or so excellent Zuikos, I had a 35/2.8
Zuiko which was an under performer. I got another example and it performed
much better.
I hope this helps.
At 04:31 PM 12/13/99 -0600, you wrote:
>On Mon, 13 Dec 1999 12:22:36 -0800 (PST), Joseph wrote:
>
>>====================================
>>Take another look:
>>
>>200mm f/5 Zuiko (single-coated)
>>
>>Vignetting = A
>>Distortion = slight pincushion
>>Aperture Center Corner
>>
>>f/5 B- B-
>>f/8 B B-
>>f/11 B+ B
>>f/16 A- B+
>>f/22 B+ B
>>f/32 B B-
>>====================================
>
>>Second, the lens isn't very sharp until f/11 as these numbers show.
>
>On that we disagree. Remember that Gary cautions againt interpreting
>his results as significant on partial grade levels. A B- lens may nor
>be presumed to be inferior to a B+ lens
>
>> A
>>lens with moderately low contrast that has to be stopped down to f/11 to
>>sharpen the corners is not a very good lens.
>
>And strangely, my shots with the 200/5 are very sharp at all
>apertures.
>
>A Tamron 200/3.5 can do better
>>than this, and the 200/4 Zuiko (which is sharp by f/5.6 and produces images
>>with high contrast) is much better.
>
>As several subscribers have noted from their personal use, magazine
>lens tests, and other private lens tests, the 200/5 consistently
>shows up as an excellent lens, fully comparable to the 200/4.
>
>I'm not sure why the 200/5 is such a burr under your saddle, and I'm
>willing to concede that you didn't like your lens. Maybe you just had
>a bad one. However, a search of the list archives will show that the
>200/5 users here have gotten excellent results from this lens, and
>test results support the conclusion that it is fully comparable to
>the 200/4. Further, its small size and economical price tag make it
>suitable for use when the "quality at all costs" 250/2 isn't an
>option.
>
>BBB
>-
>B.B. Bean - Have horn, will travel
>bbbean@xxxxxxxxxxxxxx
>Peach Orchard, MO
>http://www.beancotton.com/bbbean.shtml
>
>
>< This message was delivered via the Olympus Mailing List >
>< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
>< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
>
Kurt Hurley IDS 2000 Product Marketing Manager
Schlumberger T&T - Diagnostic Systems
1601 Technology Drive San Jose CA 95110
email khurley@xxxxxxxxxxxxxxxxxxx
PH 408-437-5156 FAX 408-437-9031 PG 408-699-4587
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|