Hi all! A friend of mine (though he's shooting with Nikons) and I both have an older AF version of a Sigma 1.4X TC, and I use it on my Canons and he on Nikons.
We started to discuss the quality, and noticed that vignetting may be somewhat heavier on pictures taken with my EOS than those taken with Nikon. And the model of the TC is exactly the same, and the lenses are comparable by focal length, max aperture and optical quality. Then, my friend spotted (he just emailed me) that on a test in a Swedish (no, for God's sake, I'm not Swedish! ;) ) photog mag FOTO they marked that most 3rd party TCs perform more poorly (talking about vignetting, not the sharpness or anything else) with EOS lenses that with Nikkor lenses. Can this be true? My friend thought/asked that can it be due to the large diameter of thje EF bayonnet compared to eg Nikon's own? Maybe Canon uses larger diameter with lenses, too, and therefore 3rd party TCs that have smaller lens diameter, caud more vignetting with EF than Nikkor (or Minolta or...) lenses. If someone is an expert on this (I'm not) please tell us how it is. Regards from FINLAND, Petja * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
