Hi ive just bought a mk2 version of this extender to use with my Canon EF 100-400 lens, on a Canon 1200D. It wont auto focus with the extender fitted, the guy i bought from said he used with his 100-400, no problems What am i doing wrong David
i dont have any exp with the 1.4 i only have a couple of x2's, until someone else comes along with an answer have you checked the obvious stuff like you not knocked the cam or lens into manual focus.
Yes hi, ive switched all the buttons, with extender off it works fine on autofocus, put it on, only manual
Any ideas what model of camera that the seller used it on? Also, do you have the latest firmware installed on your camera? Gary
I believe the 100-400 lens is too slow for the extender. If you're lucky it will work in center focus mode only. Try selecting that option. Let us know how you make out.
My line of thought is that I think that some models will af at f8. But those models would be the more professional ones. Gary
HI David, I saw your email. Personally I have not used the extender and that lens combination, but yes the lower end cameras don't really work with AF and the extender. The 5d2 you borrowed is a slight surprise as I expect it would have performed better. An extender will steal a lot of light. I read that some have got their extender to AF by taping over some contacts on their lens, and then it focuses very very slow. I don't recommend this. With such long reach you are probably best off manually focusing anyway.
two 2x canon teleconverters between my sigma 100-400c and M50 with 47mm of tube as well. that's 2mm of ruler on the 1.6 crop sensor, no cropping straight from jpeg. yes it still auto focused, slower but it still worked. if i remember i used a 10sec timer to take a shot, also i probably used manual focus on this one, the settlement movement at that mag was crazy. thats the setup that the neewer ext tube couldn't handle and snapped. i used a 13mm tube to stack the mk iii x2's as you cant stack them directly as the lens elements stick out past the body. i need to build a dedicated lens/camera bed and a get 3 axis subject stand to make full use of this set up, now i have the 100mm laowa macro i might be able to make use of that in the equation.