Sigma 1.4 TC

[Lynton]

Hi,

Am thinking of buying a 1.4 Sigma TC to use with lenses on my Pentax K-m, though apparantly it seems that the 1.4 TC is not compatible with the Sigma 120-400 lens.

Anyone know if this is true (according to Sigma;s website it is the case - but their website has never been that accurate (in my opinion))

Any comments appreciated.

 

[RichardC27]

I have the 120-400mm lens for a Canon body, and the 1.4x and 2x TC's are both compatible with it, although it will lose autofocus capability

 

[MDR]

I think it is the HSM that won't work on Pentax with the Sigma 1.4 tele converter at the moment. I presume it is for the same reason that the newer Kenko teleplus tele converters won't work with Pentax SDM only lenses (ie no contacts in the tele converter to drive the motor in the lens). Hopefully Pentax, Sigma and Kenko will produce updated tele converters soon for the new lenses appearing without screw drive focusing.

 

[arclight]

Hi,

Am thinking of buying a 1.4 Sigma TC to use with lenses on my Pentax K-m, though apparantly it seems that the 1.4 TC is not compatible with the Sigma 120-400 lens.

Anyone know if this is true (according to Sigma;s website it is the case - but their website has never been that accurate (in my opinion))

Any comments appreciated.

I can definately confirm that converter will not work with the Pentax fit 120-400mm. (Also confirmed by the instructions with the lens)
I have that lens and bought that converter. The lens goes on, but will not lock into place. I had to send the t/c back.

As an aside the, 120-400 is quite a brute of a lens so I was not too disappointed at not being able to attach another device to it.