i have totally took this for granted but as i was talking to another BF member today and surprised him i thought maybe i should share with you guys and gals!
and now onto my point.....if you use the sigmonster 300-800mm you can use a kenko 1.4x (pro 300 dg) converter with it, you still retain autofocus AND an aperture of f5.6. this is awesome in my opinion and just wanted to share with you guys if you was not aware. also of note is the converter on the lens is very good with hardly any degredation in image quality!
ok i shall shut up now.....apologies if you already know of this info.
Aperture does not stay at f/5.6. The converter does not report its presence to the camera, so even though the actual aperture is f/8, camera thinks it is f/5.6.
By the way, Romy has quite a bit of experience using the Sigmonster with TC:
http://www.birdforum.net/reviews/sh...php?product=158
http://www.pbase.com/liquidstone/sigmonster2x
or even this:
http://www.pbase.com/liquidstone/16x_tc