Sigma 1.4x teleconverted - NOT EX NOT APO NOT DG

[samal]

mostly out of curiosity I picked up a sigma 1.4x teleconverter to try it on my 70-200 2.8 EX DG HSM lens.

it was a weird one - not the usual APO EX DG, none of these markings. I googled and search and I found absolutely nothing on the teleconverter that from sigma that is not labeled APO, DG and/or EX

Sigma 1.4x Teleconverter for Canon - eBay (item 320332319962 end time Jan-21-09 03:10:29 PST)
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as you can see - very cheap so I bought it. I got it today and try to fit on on the lens - noticed that it requires more force to fit on the lens or on the body than I was willing to apply and took a step back. the mount looks identical except for the lands layout on the teleconverter's side facing the body. I started thinking that I might of pick up some kind of not EF/EF-S mount for Canon, so I took some pictures and would like to hear your opinions on what is it. What's interesting, the pins on the body - Xsi looks exactly like the pins on the lens side of the converter...

thanks

here are 3 shots of the teleconverter:

as a reference - here is the picture of the back end of my 70-200:

 

[samal]

looking up in Wiki - I was able to confirm that it is a right mount - EF

File:Canon EF lens mount.jpg - Wikipedia, the free encyclopedia

but now the question, is it normal that it requires way more strength to put on than a lens?

 

[samal]

never mind I guess - encouraged by WIKI that there was no misterious Canon mount besides FD that I didn't know about, I went ahead and tested it first on my nifty fifty - I was able to fit it on - it became easier after first time, but AF didn't work as was expected. However on my both sigma lenses AF worked perfectly and I was able to compare the zoom.

but still? I can't find even one reference on whole wide web about non APO, non EX non DG Sigma 1.4 teleconverter. it says "multi-coated lens made in Japan" on the other side. Is it some kind of fake sigma? Chinese knockoff?

from 10 feet
70mm:

with converter - 70 (97) mm

200mm:

with converter - 200 (279) mm

Thanks for your help, guys it was really interesting thread

 

[WTF?]

yeah i spose theres always the chance its a fake, seeing as youc ant find any info and its from ebay, but it seems to work fine so i guess it doesnt really matter.

on a side note, wow! look at those crazy electrical sockets!

 

[Overread]

my sigma TC is a bit stiff when connecting to my 150mm macro, but it does not need much force ot attach the two - certainly I don't feel like I am forcing them together.

Might be that you either have a very old model or a ripoff version - try some outside shots for testing (inside really is too dim for good exposures )