crofter wrote in post #18832346
Just tried a Kenko 2x pro 300 DGX (blue dot) with my R and 100-400 mk2,works OK, focus a bit slow,doesn't alter the displayed aperture so it's as if it wasn't there,as John says there have been many Kenko versions over the years,some of the older ones can be troublesome with newer cameras or lenses.
The older ones work fine, if we're talking 10 or more years ago. I bought the Pro 300 DGX when it came out, several years ago, and as I said it worked great on the 6D and 7D, doing what no proper TC should be expected to do: giving AF at f/8 in f/5.6 AF points, while also gving correct EXIF info, which it gave even if you stacked it with another TC. The older DG (what the DGX was supposed to replace) is what I currently use, virtually glued between the 7D2 and 400/4DO II, and it is visibly as sharp and contrasted as not using the TC. This DG has always worked as designed.