ballsafire wrote:
I looked at the listings and find no Canon (TC) telle converters (all Olympus); no prices, etc. I found nothing helpful. Thanks for the effort as worthless as it was to me and my Canon T1i/500D EOS camera. I just think it was a mistake in posting the wrong information, wasn't it?
The front teleconverters attach by means of the filter ring of the lens and can attach to any although one having a fixed front element and internally focusing is best. the olympus a200 and b300 are the best that olympus do and have better iq than the vivitar you were looking at.
They are interesting in that they don't cost you light (or very little) there are others which might be worth a look
this page links to most of his other pages which include tests of different extenders. His research was primarily concerned with the panasonic fz 30 which has a pretty small sensor. The larger the sensor the more of the lens gets used. So with the teleconverters there is a minimum focal length that these lenses work with.
It is worth noting that the camera's he was working with don't have interchangeable lenses so this was the best he could do. Your canon does have other options including m42 lenses via an adapter they would be manual focus but probably a better cheap alternative to this kind of lens.
If you are still curious about this kind of lens they can be found on ebay but to be fair they tend to be made for video camera's rather than still camera's. The info i have given you is about front extenders which is what you were asking about.