Notice to customers using Sigma Tele Converters for Pentax mount

SIGMA APO TELE CONVERTER 1.4x EX DG for Pentax mount and APO TELE CONVERTER 2x EX DG for Pentax mount are not compatible with lenses epuipped with HSM. Therefore, these Tele Converters cannot be used with the APO 50-150mm F2.8 II EX DC HSM for Pentax mount and APO 70-200mm F2.8 II EX DG MACRO HSM for Pentax mount.

Please refer to the list below for compatibility of Sigma Tele Converters.
APO TELE CONVERTER 1.4x EX DG for Pentax mount

It is possible to use AF
APO 70-200mm F2.8 EX DG, APO 70-200mm F2.8 EX
APO 100-300mm F4 EX DG, APO 100-300mm F4 EX IF
APO 300mm F2.8 EX DG, APO 300mm F2.8 EX

It is only possible to use MF
APO 50-500mm F4-6.3 EX DG, APO 50-500mm F4-6.3 EX RF
APO MACRO 180mm F3.5 EX DG, APO MACRO 180mm F3.5 EX IF
APO TELE MACRO 300mm F4, APO TELE MACRO 400mm F5.6
APO 500mm F4.5 EX DG, APO 500mm F4.5 EX
APO 800mm F5.6 EX DG, APO 800mm F5.6 EX
APO TELE CONVERTER 2x EX DG for Pentax mount

It is possible to use AF
APO 70-200mm F2.8 EX DG, APO 70-200mm F2.8 EX
APO 300mm F2.8 EX DG, APO 300mm F2.8 EX

It is only possible to use MF
APO 50-500mm F4-6.3 EX DG, APO 50-500mm F4-6.3 EX RF
APO 100-300mm F4 EX DG, APO 100-300mm F4 EX IF
APO MACRO 180mm F3.5 EX DG, APO MACRO 180mm F3.5 EX IF
APO TELE MACRO 300mm F4, APO TELE MACRO 400mm F5.6
APO 500mm F4.5 EX DG, APO 500mm F4.5 EX
APO 800mm F5.6 EX DG, APO 800mm F5.6 EX

Sigma lenses, expect those in the above list, cannot be attached to Sigma Tele Converters. Sigma APO Tele Converter 1.4x and 2x are dedicated to Tele Converter lenses, which should only be used with the above lenses.

Please do not use the APO Tele Converter on top of another APO Tele Converter, or any other kind of converters.

AF function of Pentax mounts cannot be used with SFX / SF7 Cameras.