Converter compatibility
 

I have today ordered a Sigma 1.4x DG convertor APO. Maybe a bit too late I double checked the spec on the Sigma web site (after ordering - foolish I know!). See http://www.sigma-imaging-uk.com/acce...-converter.htm

I am concerned about where it says thay this converter is specifically for the 2 Sigma lenses mentioned. Does this imply that it will not work with my Bigma and my other Canon lenses or merely that it will not AF with other slower lenses.

Will it AF with my Sigma 105mm Macro. Although I have bought it specifically for use with the Bigma, knowing that I will lose AF, I would like the versatility to use it with my other lenses.

Also, though not important, can this converter be used with EF-S lenses?

It has a protruding front element so be careful which lenses you try to fit to it in order to avoid damage!

I think you have a facility to 'lock out' the 50mm end of the Bigma in order to use this and the 2x convertors without mishap but do check on other lenses - test the zoom and focussing over the entire range whilst looking at the back of the lens to see how close the rear element comes to the back of the lens.

You have much the same problem with Canon TC. They will only physically fit a few of L Zoom models and L primes which are over a certain focal lenght.

For Kennygee,
I have the 105/2.8 sigma (nikon fit) and the 1.4x sigma apo converter.The two DO NOT fit together, because the rear element of the lens protrudes out of the lens tube, and the front lens element of the converter also protudes, thus the two CANNOT be physically joined.The Kenko 1.4x does fit and also retains meter, and AF functions.The Kenko converter is of a different "design" ie the lens elements are recessed well back inside the converter and therefore allow the 105 to fit inside the converter.
The 50-500 sigma has a zoom lock which I think inhibits the zoom from working in the 50-100 (not sure of exact nos) range when a sigma converter is fitted , this is to stop the rear element of lens crashing into the front element of the converter.So ineffect you end up with 100-500 lens plus the multi factor of your converter. You should be able to confirm the above from the Sigma site.
regards Subzero

Subzero

Thanks for your reply to my query. It would seem from your experiences that the best solution would be to contact Warehouse Express and change my order to the Kenko Pro.

I will ring them on Monday. Thanks very much for all replies.