I have on order a Contax Planar 85mm f/1.4 lens which weighs about 21 oz. (595 grams). I'm not sure of the lens adapter weight (Fotodiox?) but I think it may be about 4 to 5 oz., bringing total weight (without a lens hood) to at least 25 to 26 oz.
I am planning to use the lens with the camera mounted on a tripod much of the time, so the camera's lens mount will be bearing more weight than any Panasonic lens weighs, but a good measure. For comparison, the heaviest Lumix lens available at present is the new 100-300, which weighs 18.3 oz. (520 grams).
Does anyone know if this will be too much weight for the GH camera mount to safely support when the camera is tripod mounted?