We don’t have a weight specification for the
adapters as there are more factors at work than weight that
determine the stability of the connection (leverage,
thickness, etc.), and we don’t endorse any use for them but to
attach one filter or lens cap to a lens. Users have told us
that they use them for closeup lenses, but you would need to
test them yourself (carefully) and decide if you are
comfortable with the stability.
FYI, we are considering adding a heavy duty
adapter for matte boxes, closeups, and/or Lee filter setups,
but not until sometime next year at the earliest.
Sorry I can’t be more help. We like to remind
folks that the XUME connection is temporary by design, so
please factor that into your use.
Many thanks for your interest!
I'm wondering whether this set is
capable of holding the Canon 72 mm 500D close up lens.
It weighs 120 g. My Panny 100-400 lens has a short
slide-out hood, which would protect from side impacts.
Thanks,
Moose