----- Original Message -----
From: "F. Craig Callahan" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, April 02, 2001 2:51 AM
Subject: EOS Re: IS vs. non-IS Sharpness (300/4L)
> Note too that the MTF graphs in the "L" lens brochure (Pub.
> CT2-1505-004) for the two 300/4L lenses, while not the easiest to
interpret (at
> least for me) would appear to support Photodo's results.
>
I don't think I agree with that. I just had a look at the MTF graphs in the
Canon Lens Work, and the IS version is better in allmost every aspect. It
has both better sharpness and contrast, allthough I do notice a 'less flat'
sharpness curve in the IS compared to the non-IS, but it still ends up
better than the start of the non-IS version. The only aspect where I expect
the IS to perform a bit worse would be in flare.
With more elements, common logic would have it that it must be worse than
the predecessor; yet, today optic and coating quality and lens design is
better than in the past and it is possible to produce better lenses with
more optical elements.
As for the photodo result: can you really tell after testing only one lens?
The original 300/f4 might have been a very good one or the IS not so good. I
have a lot of questions about test consistency and accuracy with the photodo
tests.
My real-world usage of the 300/f4 IS certainly suggests that it is very
sharp, and I doubt very much that the non-IS would have done any better. In
fact, many of my photographs simply would not have been possible with the
normal 300/f4. I'm fighting with the idea at present of trading it in for
the 300/2.8IS since I'll battle to justify having both; but it is really
nice to have such a close focusing, portable lens as the 300/f4IS. The shot
of a leopard on my website at
http://home.mweb.co.za/te/teknovis/T-M0031%20Leopard%20portrait%204.htm has
been used for a glossy brochure cover and another leopard shot, also with
the 300/f4IS (not on my web page) has recently been used as a magazine
cover. I can assure you, it is a sharp lens and very useful.
Regards
Thys
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Thys van der Merwe
Portfolio of African Images:
http://home.mweb.co.za/te/teknovis
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