"Gary Fisher" <[EMAIL PROTECTED]> wrote/replied to: >The EX Sigmas are designed for their high-end/pro lenses. They also fit the same >Canon L lenses that genuine EF converters do. There's a compatibility chart on their >US website: > >http://www.sigma-photo.com/html/pages/ConvComptChart.htm > >The Kenko Pro and Tamron SP (same TCs, just marketed under different brands) have the >additional pins and report correct (i.e. adjusted) aperture to the camera just like >the Canon ones do. So a 1.4x would report the f5.6 @ 400mm on your lens as F8 @ >400mm.... > >They do however work with all lenses, as they don't have a protruding front element. >They are also pretty comparable to the Canon ones in quality (at least the 1.4x is, >the 2x is reportedly so and I have no idea what the optical quality of the 3x would >be like). > >From the notes on the Sigma web site it sound like the Sigmas TCs report adjusted >apertures as we
Thanks, I think I'll pick up an older Kenko then. I think they made a 1.5x. I'm real happy with the Kenko MC7 2X, so the 1.5x should be even better, and will give me AF at least most of the time. It just won't be quite as long, but I'll have to live with that. Course I won't be throwing out my 2X either... Jim Davis Nature Photography http://www.kjsl.com/~jbdavis/ * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
