Question about Canon 100-400 IS lens

Judit Fabian wrote:
 > I have read in a lens review forum that some kind of a "taping trick"
 > enables AF when using the 1.4 TC with this lens. Can anybody tell me what
 > this "trick" is?

Buying a EOS 3, 1v, 1D or 1Ds.

The other solutions is insulating the three additional contacts
the TC has, but do not expect anything than poor AF performance.


--
Helmut Faugel<!-- ~MESSAGE_AFTER~ -->
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  >> Judit Fabian wrote:

  >> I have read in a lens review forum that some kind of a "taping trick"
  >> enables AF when using the 1.4 TC with this lens.

 >From: Helmut Faugel FAUGEL DeleteThis @ipp.mpg.de
 >
 >Buying a EOS 3, 1v, 1D or 1Ds.
 >
 >The other solutions is insulating the three additional contacts
 >the TC has, but do not expect anything than poor AF performance.

I agree with Helmut, the camera will TRY to AF and if there's enough contrast
it will do it, but it's not reliable. The bodies he mentions allow AF at f/8
min aperture, which is really nice.

Bill<!-- ~MESSAGE_AFTER~ -->
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Bill Hilton wrote:

   > >> Judit Fabian wrote:
 >
   > >> I have read in a lens review forum that some kind of a "taping trick"
   > >> enables AF when using the 1.4 TC with this lens.
 >
  > >From: Helmut Faugel FAUGEL.DeleteThis@ipp.mpg.de
  > >
  > >Buying a EOS 3, 1v, 1D or 1Ds.
  > >
  > >The other solutions is insulating the three additional contacts
  > >the TC has, but do not expect anything than poor AF performance.
 >
 > I agree with Helmut, the camera will TRY to AF and if there's enough contrast
 > it will do it, but it's not reliable. The bodies he mentions allow AF at f/8
 > min aperture, which is really nice.

In my opinion the 100-400 IS L is not sharp enough to warrant
any TCs. Just enlarge your straight image, it'll be just as good.

I just got the 300 f/4 L prime and it is much sharper.
(I do love the zoom of the 100-400, but I'll probably not
use it much anymore).

Roger<!-- ~MESSAGE_AFTER~ -->
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On Fri, 07 Nov 2003 21:48:12 -0700, "Roger N. Clark"
<rnclark.RemoveThis@qwest.net> wrote/replied to:

 >In my opinion the 100-400 IS L is not sharp enough to warrant
 >any TCs. Just enlarge your straight image, it'll be just as good.

at times I think the same but sometimes when I have enough light and a
tree to steady against my results with a 2X are superb. Way better
than just enlarging the lens without.

 >I just got the 300 f/4 L prime and it is much sharper.
 >(I do love the zoom of the 100-400, but I'll probably not
 >use it much anymore).

Did you get the IS model? I heard that's not such a sharp lens, heh
heh. Hey, I'm not being picky here, but some people are. How sharp is
sharp enough anyway? I can make excellent 12 by 18 photos with the
100-400, and that's good enough for me. yes, with 2X I can also make
12 by 18s.<!-- ~MESSAGE_AFTER~ -->
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Jim Davis wrote:

 > On Fri, 07 Nov 2003 21:48:12 -0700, "Roger N. Clark"
 > <rnclark.TakeThisOut@qwest.net> wrote/replied to:
 >
  > >In my opinion the 100-400 IS L is not sharp enough to warrant
  > >any TCs. Just enlarge your straight image, it'll be just as good.
 >
 > at times I think the same but sometimes when I have enough light and a
 > tree to steady against my results with a 2X are superb. Way better
 > than just enlarging the lens without.
 >
  > >I just got the 300 f/4 L prime and it is much sharper.
  > >(I do love the zoom of the 100-400, but I'll probably not
  > >use it much anymore).
 >
 > Did you get the IS model? I heard that's not such a sharp lens, heh
 > heh. Hey, I'm not being picky here, but some people are. How sharp is
 > sharp enough anyway? I can make excellent 12 by 18 photos with the
 > 100-400, and that's good enough for me. yes, with 2X I can also make
 > 12 by 18s.

Yes, the IS model. I do my testing on a tripod and use both real
scenes and test targets. With a 10D, which has spatial
resolution similar to ISO 50 Velvia, the 300 f/4 is sharp
down to the pixel at f/4. The 100-400 is blurred by several
pixels, especially at 400. I can make really nice 8x10s
with the 100-400, but it is soft above that. As a large format
photographer, I'm pretty picky about sharpness.
See images, articles on sharpness and test results at:
<a style='text-decoration: underline;' href="http://www.clarkvision.com" target="_blank">http://www.clarkvision.com</a>

Roger<!-- ~MESSAGE_AFTER~ -->
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