Originally posted by Squawk I did find on one of Ricoh's websites last night under the specifications it now says 20mm-2.8;4.0 and 40mm-4.0;5.6.
They would probably be referring to the notorious "35mm equivalence",
meaning that in terms of depth of field,
f/2.8 on APS-C is "equivalent" to f/4 on 35mm full frame,
or f/4 "equivalent" to f/5.6.
Previously, they have given "equivalent" focal lengths (30.5 - 61.5 mm).
You can search under "equivalence" on this website
for endless discussions of the topic,
but you'll do far better getting to know and use your new equipment!