looking for canon fd extendersgreenspun.com : LUSENET : Canon FD : One Thread
I am looking for the extenders that match the canon 300 2.8L fd mount , I think they are white colored. I am looking for both the 1.4 and the 2x extenders.
If I want to use the normal fd 2x , I read that for this lens canon recommends the use of the 2xb even though it was made for up to 300mm. Is that correct?
-- shai (firstname.lastname@example.org), November 07, 2001
Yes, Canon recomends the 2xB for that lens. I suspect it has something to do with the high speed of the lens - a more complex teleconvertor (2xB) is needed.
Here's a link to a blurb from Canon: http://www.canonfd.com/lwond/page42.htm
Also, I've never seen any white FD teleconvertors; I believe the EOS units come in white.
-- Duane K (email@example.com), November 08, 2001.
A partial answer is on this forum at: http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=0059LR
The optical formula differs between the two, and, if I remember correctly, one of the extenders portrudes past the mount plane of the lens; thus it's unsuitable for lenses whose rear element is even with the mount plane.
-- Joshua Martin (firstname.lastname@example.org), November 08, 2001.
According to the following site, extenders were bundled with the new 300/2.8L lenses (look for the red text box): http://www.mir.com.my/rb/photography/companies/canon/fdresources/fdlen ses/extenders.htm
I don't have a 300/2.8, so what follows is hearsay from the guys on the Canon FD mailing list at http://www.kjsl.com/canon-fd/ .
I quote: " The 2X-A is optimized for use on Canon lenses of 300mm and up. The 2X-B is optimized for use on Canon lenses of under 300mm.
Except for the FD 300mm f/2.8, which for some reason works best with the 2X-B.
So, if you want a doubler for a lens under 300mm, use the "B" and if you need to double a 300mm or longer lens, use the "A" unless it's a 300/2.8......."
One more quote: "To my little knowledge, the 300mm F2.8 FL-F lens was one that DID come with the tidbits: This lens was originally only available by special order and the 2X converter was designed specifically for this lens. As Canon put it in a brochure dated December, 1973, "This lens was computer designed with the Extender 2X as part of its optical formula, so there is no image degradation." "
That's all I can offer. Try a web search and see what you come up with.
-- Joshua Martin (email@example.com), November 09, 2001.