yongnuo 2x III extender/ 50mm 1.4

[jefflinde]

I was cruising around the Yongnuo website and i saw a 2X extender and a 50mm 1.4 listed. Does anyone have any experience with these and if so what are your thoughts? Also, where did you acquire them as I can not locate them for sale anywhere. Especially the 50mm 1.4

http://hkyongnuo.com/e-detaily.php?ID=353

http://hkyongnuo.com/e-detaily.php?ID=350