Quoted By:
>reply from Metabones:
>Please refer following information for your reference.
>The 0.64x XL was designed to give really great performance over the slightly cropped 4k format of the Panasonic GH4 camera, and it really excells over this smaller format even at apertures down to f/0.80 . Of course, the XL does function perfectly well over the full M43 format, but there is a gradual drop in MTF toward the corners at large apertures. Once you stop down to about f/2 or slower, however, you should be hard-pressed to find image flaws with the XL even in the extreme corners of the full M43 format.
>By comparison, the 0.71x ULTRA has much more even center-to-corner performance over the full M43 format, especially at large aperture.
>If you want a general-purpose Speed Booster for shooting stills and video on M43 then the ULTRA is the better choice. However, if you are mainly shooting 4k video on the GH4 and want the greatest possible focal length reduction, then the the XL is the better choice.
I still can't decide clearly. I am going to simultaneously buy a gh4 and a metabooster. I will def shoot 4K video (and edit it in 1080p/scale mode to have the option to export in 2/4K if needed).
I am not worried about photos, I am sure the gh4 will be fine with either speedboosters.
