What focal length lens is the teleconverter made for? I believe some are made for longer lenses like 300+ and some for shorter so check your manual and see or just give it a go and find out.
to my knowledge none of them are made for longer / shorter, the "official" list that canon supports is pretty limited and is mostly prime lenses
I cant imagine it working very well with a fisheye... and not sure what you would try to get from it, your better off using a regular lesn and the doing the fisheye effect in PS I think
stolen from B&H which is probably from canon anyway
<table border="0" cellpadding="4" cellspacing="1"><tbody><tr><td colspan="5" bgcolor="#eeeecc">
[FONT=Verdana, Arial, Helvetica, sans-serif]Extender EF 1.4x II Compatibility Chart[/FONT]</td> </tr> <tr valign="top"> <td bgcolor="#ddddff" nowrap="nowrap" width="244">
[FONT=Verdana, Arial, Helvetica, sans-serif]Lens Attachment[/FONT]
</td> <td align="center" bgcolor="#ddddff" nowrap="nowrap" width="93">
[FONT=Verdana, Arial, Helvetica, sans-serif]Focal Length
(mm)[/FONT]
</td> <td align="center" bgcolor="#ddddff" nowrap="nowrap" width="72">
[FONT=Verdana, Arial, Helvetica, sans-serif]f-stop
(f)[/FONT]
</td> <td align="center" bgcolor="#ddddff" nowrap="nowrap" width="136">
[FONT=Verdana, Arial, Helvetica, sans-serif]Max. Magnification
(x) [/FONT]
</td> <td align="center" bgcolor="#ddddff" width="71">
[FONT=Verdana, Arial, Helvetica, sans-serif]AF[/FONT]
</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 135mm f/2L USM[/FONT]
</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
189[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
2.8 ~ 45[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.27[/FONT]</td> <td align="center">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 180mm f/3.5L Macro USM[/FONT]
</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
252[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
4.5<sup>*1</sup> ~ 45[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
1.40[/FONT]</td> <td align="center" bgcolor="#eeeeee">[FONT=Verdana, Arial, Helvetica, sans-serif]
O<sup>*3</sup>[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 200mm f/1.8L USM[/FONT]
</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
280[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
2.5 ~ 32[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.12[/FONT]</td> <td align="center">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 200mm f/2.8L II USM[/FONT]
</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
280[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
4 ~ 32[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.22[/FONT]</td> <td align="center" bgcolor="#eeeeee">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 300mm f/2.8L IS USM[/FONT]
</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
420[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
4 ~ 45[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.15[/FONT]</td> <td align="center">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 300mm f/4L IS USM[/FONT]
</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
420[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
5.6 ~ 45[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.33[/FONT]</td> <td align="center" bgcolor="#eeeeee">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 400mm f/2.8L IS USM[/FONT]
</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
560[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
4 ~ 45[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.22[/FONT]</td> <td align="center">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 400mm f/4L DO IS USM[/FONT]
</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
560[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
5.6 ~ 45[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.17[/FONT]</td> <td align="center" bgcolor="#eeeeee">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 400mm f/5.6L USM[/FONT]
</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
560[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
8 ~ 45[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.18[/FONT]</td> <td align="center">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 500mm f/4L IS USM[/FONT]
</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
700[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
5.6 ~ 64[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.17[/FONT]</td> <td align="center">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 600mm f/4L IS USM[/FONT]
</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
840[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
5.6 ~ 64[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.17[/FONT]</td> <td align="center" bgcolor="#eeeeee">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 1200mm f/5.6L USM[/FONT]
</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
1,680[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
8 ~ 45[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.12[/FONT]</td> <td align="center">[FONT=Verdana, Arial, Helvetica, sans-serif]
X[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 70-200mm f/2.8L USM[/FONT]
</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
98 ~ 280[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
4 ~ 45[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.22[/FONT]</td> <td align="center" bgcolor="#eeeeee">[FONT=Verdana, Arial, Helvetica, sans-serif]
O<sup>*2</sup>[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 70-200mm f/2.8L IS USM[/FONT]
</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
98 ~ 280[/FONT]</td> <td align="center" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
4 ~ 45[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.24[/FONT]</td> <td align="center">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 70-200mm f/4L USM[/FONT]
</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
98 ~ 280[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
5.6 ~ 45[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.31[/FONT]</td> <td align="center" bgcolor="#eeeeee">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 70-200mm f/4L IS USM[/FONT]
</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
98 ~ 280[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
5.6 ~ 45[/FONT]</td> <td align="center" bgcolor="#ffffff" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.31[/FONT]</td> <td align="center" bgcolor="#ffffff">[FONT=Verdana, Arial, Helvetica, sans-serif]
O[/FONT]</td> </tr> <tr> <td bgcolor="#eeeecc" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif]EF 100-400mm f/4.5-5.6L IS USM[/FONT]
</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
140 ~ 560[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
6.7 ~ 54<sup>*1</sup>[/FONT]</td> <td align="center" bgcolor="#eeeeee" nowrap="nowrap">[FONT=Verdana, Arial, Helvetica, sans-serif]
0.28[/FONT]</td> <td align="center" bgcolor="#eeeeee">[FONT=Verdana, Arial, Helvetica, sans-serif]
O<sup>*4*5</sup>[/FONT]</td> </tr> <tr> <td colspan="5" nowrap="nowrap">
[FONT=Verdana, Arial, Helvetica, sans-serif](O =possible X =impossible)
[/FONT]
</td> </tr> </tbody></table> <table border="0" cellpadding="4" cellspacing="1" width="616"><tbody><tr bgcolor="#eeeeee" valign="top"> <td height="26" width="20">[FONT=Verdana, Arial, Helvetica, sans-serif]
*1[/FONT]</td> <td height="26" width="596">[FONT=Verdana, Arial, Helvetica, sans-serif]
Data based on EOS models with exposures displayed in 1/2 stop increments. It varies slightly with the EOS-1v, EOS-1N, EOS-1 and EOS-3.[/FONT]</td> </tr> <tr bgcolor="#eeeeee" valign="top"> <td height="27" width="20">[FONT=Verdana, Arial, Helvetica, sans-serif]
*2[/FONT]</td> <td height="27" width="596">[FONT=Verdana, Arial, Helvetica, sans-serif]
If the EF 70-200mm f/2.8L USM lens is attached to an EOS camera having multiple focusing points and an Extender is attached to the lens, only the center focusing point will be usable for AF.[/FONT]</td> </tr> <tr bgcolor="#eeeeee" valign="top"> <td height="14" width="20">[FONT=Verdana, Arial, Helvetica, sans-serif]
*3[/FONT]</td> <td height="14" width="596">[FONT=Verdana, Arial, Helvetica, sans-serif]
The autofocusing range is from 0.8m/2.6ft. to infinity.[/FONT]</td> </tr> <tr bgcolor="#eeeeee" valign="top"> <td height="14" width="20">[FONT=Verdana, Arial, Helvetica, sans-serif]
*4[/FONT]</td> <td height="14" width="596">[FONT=Verdana, Arial, Helvetica, sans-serif]
AF is ONLY possible with the EOS-1v and EOS-3 cameras, ONLY when using the center focusing point.[/FONT]</td> </tr> <tr bgcolor="#eeeeee" valign="top"> <td height="26" width="20">[FONT=Verdana, Arial, Helvetica, sans-serif]
*5[/FONT]</td> <td height="26" width="596">[FONT=Verdana, Arial, Helvetica, sans-serif]
The Image Stabilizer does not operate with the following cameras: EOS 650, 620, 630/600, RT, 700, 750, 850, EOS-1, A2/A2E, 10s, Elan, Rebel/Rebel S, Rebel II/Rebel SII.[/FONT]</td></tr></tbody></table>