and referring to the parts list, majority of mechanical parts use "SC"
prefix which to me has always meant "SubContractor". From a service
standpoint, it's like comparing inner construction of the 310 flash with
the T32, 2 completely unrelated approaches.
___________________________________
John Hermanson | CPS, Inc.
21 South Ln., Huntington NY 11743
631-424-2121 | www.zuiko.com
Olympus OM Service since 1977
Gallery: www.zuiko.com/album/index.html
Moose wrote:
> John Hermanson wrote:
>> At least the plate has 3 screws holding it all together when you
>> drop it back in. That is what tipped me off that the 35-105 zoom
>> is definitely not Olympus built. The only screws holding all the
>> blade parts in are the 3-4 screws that hold the blade assembly into
>> the barrel. You have to ...
>>
>
> I'm certainly in no position to argue with your expertise. I did make
> a modest effort (i.e. no tear-downs) to check the persistent rumor
> that it was a version of the similar spec Tokina. Here's my list of
> comparison points:
>
> ------------------------------------------------------------------ "I
> can see where someone could at a casual look think they might be the
> same underneath. They are very similar in size, weight and overall
> appearance except for very different rubber focus/zoom ring covers.
> On closer inspection, I note the following:
>
> 1. Coating reflections are different colors, indicating different
> coating design/technology, and size/depths, indicating different
> internal element shape/configuration.
>
> 2. Front mounting of the front element of the zooming group is
> slightly different.
>
> 3. The Zuiko focusing helicoid takes considerably less rotation of
> the focus/zoom ring to get to its minimum of 1.5m and than the Tokina
> takes to go to its minimum of 1.6m
>
> 4. Zoom ring travel from 35-105mm is 20.8mm on the Zuik and 20.6mm
> on the Tokina.
>
> 5. Although the close focus mechanism uses the same principle of
> acting as an extension tube, the ring moves in opposite directions on
> the 2 lenses, locks into CU position on the Zuiko, but not on the
> Tokina and has a different extension length, 6.6mm on the Zuiko and
> 8.3mm on the Tokina.
>
> 6. Both have 6 blade diaphrams that point their fingers clockwise,
> but they are mounted opposite ways, with the fingers on the Zuiko
> toward the front and the Tokina to the back. The Zuiko hexagon is
> also a bit more symmetrical and consistent as it is stopped down.
>
> 7. The rear element of the Tokina is considerably larger and mounted
> into its cell differently than the Zuiko.
>
> 8. The finish of the visible part of the mount is classic Oly matte
> on the Zuiko and shiny on the Tokina.
>
> 9. The mechanisms that convey aperture setting to the pin on the
> rear and operate the diaphram from the other pin on the rear are
> quite different designs, with the Zuiko using the same basic design
> as in other Zuikos I've had apart.
>
> 10. The Zuiko has 16 elements in 12 groups and the Tokina has 16 in
> 13.
>
> 11. Ths Zuiko is styled pretty much like the 70-150 and 35-70/3.6 &
> 35.-4.5 except fot the close-up ring, which isn't on those zooms, but
> it is in the same relative position as the zoom rings on those 2
> touch models. I assume the otherwise odd design of the CU ring with
> the groove around the middle is to differentiate it from the zoom
> rings on the others. The Tokina is styled just like the other Tokina
> zooms I have. Finish of the body surfaces is very similar.
>
> 12. The nose of the Tokina in front of the zoom ring is much shorter
> than on the Zuiko, so the Oly hood doesn't clamp on as securely. The
> Tokina hood is also a clamp-on design but is calculated for use with
> a filter and uses something like an empty filter ring for the hood to
> clamp onto when a filter isn't. The Oly solution of a clamp on hood
> that doesn't interfere with filter use is much nicer.
>
> My conclusion? It is extremely unlikely that the Zuiko is an
> adaptation of the Tokina. There are just too many differences that
> wouldn't make sense if it were, especially things like reversing and
> changing the length of travel of the CU helicoid, changing the pitch
> of the focusing helicoid and changing the internal design of the auto
> aperture mechanisms. It also really does appear to me from the
> reflections that the internal elements differ quite a bit in surface
> curvatures and/or locations."
>
> Moose
--
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