After surfing the archives, I found the following inquiry to the list from
about 2 years ago (taken verbatim):
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I've lately acquired a 300 mm F2.8 A* big glass and naturally am looking
for ways to burn off the extra F stops. If I read the materials correctly
300mm is sort of the breaking point between whether you should use an "S"
or "L" converter. Someone know which works best with this lens/focal
length?
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Surprisingly, there were only 2 responses...
Part of one response was that... "I believe the main advantage of XL
teleconverters is a reduction in light fall-off in the corners compared to
teleconverters without the long snout. The secondary advantage of XL
teleconverters is optimized image quality for their compatible lenses."
Another response mentioned, "I'd assume that the 'L' converters would work
slightly better, but I suspect you'd only see the difference under lab
conditions."
My question is, does anyone care to elaborate / confirm / disagree with
these comments? In particular, with an FA 300mm 1:2.8, would one have the
option of using either the 2x-S or the 2x-L? and if so, is the optical
difference neglible? In short I'm trying to determine if paying twice as
much for the 2x-L is necessary if the 2x-S is acceptable.
Thanks in advance,
jerome
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Jerome D. Coombs-Reyes
PhD Candidate, ISyE, Georgia Tech
http://www.isye.gatech.edu/~jerome
