Pretty sure you listed it in your initial post Andrew, but just wanted to confirm the new speedbooster XL will function well with the Sigma 18-35mm in 4k and FHD modes on the GH4? Cheers!
I'm really interested to know if I use this with my GH4 to mount my canon glass, will I be able to attach my nice old nikon ai and ai-s lenses by attaching a generic fotodiox adapter to the top end of the speedbooster?