Teleconverter on Sigma 70-300mm APO??

[cpmishra123]

Did anyone try a teleconverter on a Sigma 70-300mm APO?? I know the Canon teleconverters wont work with the sigma 70-300mm bcoz of the projection on the canon teleconverters. but i guess i have seen some snaps taken with a sigma 70-300mm and a tamron teleconverter. they were descent enough. i know i wud loose autofocus, but on tamron teleconvs autofocus is not lost as it doesn't transfer the loss of 1-stop of light to the camera. the circuitry is not present. but the i have heard that the tamron teleconv are not tat good as compared to the canon and sigma teleconvs. any idea plz update me, i wud luv to see some test snaps. thanks.

[dmwierz]

Did anyone try a teleconverter on a Sigma 70-300mm APO?? I know the Canon teleconverters wont work with the sigma 70-300mm bcoz of the projection on the canon teleconverters. but i guess i have seen some snaps taken with a sigma 70-300mm and a tamron teleconverter. they were descent enough. i know i wud loose autofocus, but on tamron teleconvs autofocus is not lost as it doesn't transfer the loss of 1-stop of light to the camera. the circuitry is not present. but the i have heard that the tamron teleconv are not tat good as compared to the canon and sigma teleconvs. any idea plz update me, i wud luv to see some test snaps. thanks.


This lens does not work with the Sigma TC's according to both Sigma and from my personal tests, the AF is definitely lost.

[Nezmo]

I can't compare to Canon or Sigma tcs but I can tell you the Tamron 1.4x tc does just fine on this lens. Only slight loss of sharpness and contrast.

[cpmishra123]

thanks nezmo. i think i should try the tamron 1.4x with my sig 70-300mm. i heard that there is vignetting with tamron TCs so i was bit worried. even thinking of trying a sigma TC too. will check if it matches and will try to compare both of them.

[Nezmo]

thanks nezmo. i think i should try the tamron 1.4x with my sig 70-300mm. i heard that there is vignetting with tamron TCs so i was bit worried. even thinking of trying a sigma TC too. will check if it matches and will try to compare both of them.
I don't recall any vignetting but I can't swear that I've tried all focal lengths with the TC on that lens.