Originally posted by ticats Has anyone used the latest Sigma 1.4X Teleconverter EX APO DG and a Pentax FA*300 mm F4.0 lens on a Pentax K5? Is it compatible with regards to AF and AE?
Any info on this combination would be helpful.
I posted a list at one time of the compatible lenses, as stated in the sigma leaflet that came with my sigma TC
if you do a search under my name as a poster, and sigma TC for key words you should find it.
the bottom line is that your lens needs to have a 35mm diameter 12mm deep opening to accept the TC without interference. I don not recall the FA300/4 lens being on the list, I think it was limited to the FA300/2.8.
check here
https://www.pentaxforums.com/forums/pentax-beginners-corner-q/50537-teleconve...tml#post484259