Thomas T. Veldhouse wrote:
wrote:

Nope. The Kenko Pro 300 1.4x is about as good as they get. I use one
with my 100-400IS, and there is no visible loss of contrast, or any kind
of distortion. It is good enough that I opt to zoom out instead of
removing it, unless lighting gets really low and I need that stop back.
The Canon TC is only useful with select Canon telephotos; you can use
the Kenko with almost any lens, although it starts to get soft and
distorted in the corners of a 1.6x-crop if you use wide-angle lenses,
wide open, with it. You can use the Kenko with macro lenses, too, to
get more magnification

Better be careful that the rear glass element of your lens doesn't smash into
the teleconverter glass for wide angle lenses. Most documentation suggests
not to use a lens shorter than, IIRC, 50mm.

Thanks. My intended use was with a telephoto, but it is good to
know that I could use it with a 50mm or longer. That could save
me having to carry too much when just "walking around".

--- Paul J. Gans